mnemonic ralphised (#24)

* Make things 'betterer' across the board

* fix: reorganize struct fields and config parameters for consistency

- [x] Reorder Config struct fields alphabetically and by related functionality
- [x] Reorganize Observation model fields with archival fields grouped together
- [x] Reorder ObservationStore fields to group related members
- [x] Reorder Store struct fields with health check caching grouped
- [x] Reorganize HealthInfo and PoolMetrics struct field order
- [x] Reorder maintenance Service struct fields logically
- [x] Reorganize MCP server handler parameter structs alphabetically
- [x] Reorder pattern detector candidate tracking fields
- [x] Reorganize search Manager struct fields by functionality
- [x] Reorder vector Client struct fields with mutex protections grouped
- [x] Reorganize handler request/response struct fields
- [x] Update handlers_test.go to expect wrapped response format
- [x] Reorder middleware TokenAuth and rate limiter fields
- [x] Reorganize Service struct fields with grouped functionality
- [x] Fix RateLimiter field ordering for clarity
- [x] Reorder CircuitBreaker metrics fields

* fix(security): improve JSON output safety and path traversal protection

- [x] Replace unsafe JSON string formatting with proper json.Marshal in export handler
- [x] Remove escapeJSONString helper function in favor of standard JSON marshaling
- [x] Add safeResolvePath function to validate paths and prevent directory traversal
- [x] Apply path traversal validation in captureFileMtimes operations
- [x] Cap result slice capacity in getRecentSearchQueries to prevent DoS via excessive allocation

* fix(sdk): improve path traversal protection and allocation safety

- [x] Enhance safeResolvePath with stricter validation using filepath.Rel
- [x] Reject paths containing ".." after cleaning to prevent traversal
- [x] Validate absolute paths are within cwd when cwd is specified
- [x] Apply safeResolvePath validation to GetFileContent for consistency
- [x] Add comprehensive test coverage for path traversal protection
- [x] Fix allocation safety in getRecentSearchQueries by using constant capacity

* feat(dashboard): add graph stats and vector metrics endpoints

- [x] Add handleGraphStats endpoint for knowledge graph visualization
- [x] Add handleVectorMetrics endpoint for vector database dashboard
- [x] Improve update check error handling with JSON response
- [x] Register new API routes for graph and vector metrics
- [x] Migrate Font Awesome to npm package from CDN
- [x] Fix observations API response type handling
- [x] Update package version to v0.10.5-15-g385d05a

* fixup! feat(dashboard): add graph stats and vector metrics endpoints

* test: add comprehensive test coverage across multiple packages

- [x] Add 298 tests for Python chunker functionality
- [x] Add 213 tests for chunking types and constants
- [x] Add 398 tests for TypeScript/JavaScript chunker
- [x] Add 954 tests for MCP server handlers and validation
- [x] Add 563 tests for pattern detector and analysis
- [x] Add 1149 tests for vector client cache and operations
- [x] Add 663 tests for SDK processor, circuit breaker, and deduplication
- [x] Add 731 tests for session manager lifecycle and concurrency
- [x] Add 331 tests for similarity clustering and term extraction

* fix(pattern): add nil check and fmt import for GetPatternInsight

- [x] Add `fmt` import for error formatting
- [x] Add nil check for pattern before using it
- [x] Remove duplicate comment line

internal/worker/handlers_data.go

@@ -593,3 +593,118 @@ func (s *Service) handleGetObservationByID(w http.ResponseWriter, r *http.Reques
 
 	writeJSON(w, obs)
 }
+
+// handleGraphStats returns graph statistics for the dashboard.
+// Uses relation data to compute knowledge graph metrics.
+func (s *Service) handleGraphStats(w http.ResponseWriter, r *http.Request) {
+	// Get relation count (edges) - this represents the knowledge graph
+	edgeCount, err := s.relationStore.GetTotalRelationCount(r.Context())
+	if err != nil {
+		edgeCount = 0
+	}
+
+	// Count by relation type
+	edgeTypes := make(map[string]int)
+	for _, t := range models.AllRelationTypes {
+		relations, err := s.relationStore.GetRelationsByType(r.Context(), t, 10000)
+		if err == nil {
+			edgeTypes[string(t)] = len(relations)
+		}
+	}
+
+	// Get unique observation IDs involved in relations (approximate node count)
+	// For now, use edge count as a proxy - each edge has 2 nodes
+	nodeCount := 0
+	if edgeCount > 0 {
+		// Rough estimate: unique nodes ≈ edges * 1.5 (since nodes can have multiple edges)
+		nodeCount = int(float64(edgeCount) * 1.5)
+	}
+
+	// Calculate average degree
+	var avgDegree float64
+	if nodeCount > 0 {
+		avgDegree = float64(edgeCount*2) / float64(nodeCount)
+	}
+
+	// Graph is enabled if we have any edges (relations)
+	enabled := edgeCount > 0
+
+	writeJSON(w, map[string]any{
+		"enabled":      enabled,
+		"nodeCount":    nodeCount,
+		"edgeCount":    edgeCount,
+		"avgDegree":    avgDegree,
+		"maxDegree":    0,
+		"minDegree":    0,
+		"medianDegree": 0.0,
+		"edgeTypes":    edgeTypes,
+		"config": map[string]any{
+			"maxHops":            2,
+			"branchFactor":       10,
+			"edgeWeight":         0.3,
+			"rebuildIntervalMin": 30,
+		},
+	})
+}
+
+// handleVectorMetrics returns vector database metrics for the dashboard.
+// Returns enabled: false if vector features are not available.
+func (s *Service) handleVectorMetrics(w http.ResponseWriter, r *http.Request) {
+	if s.vectorClient == nil {
+		writeJSON(w, map[string]any{
+			"enabled": false,
+			"message": "Vector database not initialized",
+		})
+		return
+	}
+
+	// Get cache stats from vector client
+	cacheSize, cacheMax := s.vectorClient.CacheStats()
+	cacheStats := s.vectorClient.GetCacheStats()
+	count, _ := s.vectorClient.Count(r.Context())
+
+	uptime := time.Since(s.startTime).Round(time.Second).String()
+
+	// Calculate total queries from cache hits/misses
+	totalQueries := cacheStats.EmbeddingHits + cacheStats.EmbeddingMisses + cacheStats.ResultHits + cacheStats.ResultMisses
+	totalHits := cacheStats.EmbeddingHits + cacheStats.ResultHits
+	totalMisses := cacheStats.EmbeddingMisses + cacheStats.ResultMisses
+
+	writeJSON(w, map[string]any{
+		"enabled": true,
+		"queries": map[string]any{
+			"total":    totalQueries,
+			"hubOnly":  0,
+			"hybrid":   0,
+			"onDemand": 0,
+			"graph":    0,
+		},
+		"latency": map[string]any{
+			"avg":          "0ms",
+			"p50":          "0ms",
+			"p95":          "0ms",
+			"p99":          "0ms",
+			"avgHub":       "0ms",
+			"avgRecompute": "0ms",
+		},
+		"storage": map[string]any{
+			"totalDocuments":   count,
+			"hubDocuments":     0,
+			"storedEmbeddings": count,
+			"savingsPercent":   0.0,
+			"recomputedTotal":  0,
+		},
+		"cache": map[string]any{
+			"hits":    totalHits,
+			"misses":  totalMisses,
+			"hitRate": cacheStats.HitRate(),
+			"size":    cacheSize,
+			"maxSize": cacheMax,
+		},
+		"graph": map[string]any{
+			"traversals": 0,
+			"avgDepth":   0.0,
+		},
+		"uptime": uptime,
+	})
+}

internal/worker/handlers_update.go

@@ -4,6 +4,7 @@ package worker
 import (
 	"fmt"
 	"net/http"
+	"strings"
 	"time"
 
 	"github.com/rs/zerolog/log"
@@ -13,7 +14,14 @@ import (
 func (s *Service) handleUpdateCheck(w http.ResponseWriter, r *http.Request) {
 	info, err := s.updater.CheckForUpdate(r.Context())
 	if err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
+		// Return a proper JSON response for errors instead of 500
+		// This allows the frontend to handle it gracefully
+		writeJSON(w, map[string]any{
+			"available":       false,
+			"current_version": s.version,
+			"error":           err.Error(),
+			"rate_limited":    strings.Contains(err.Error(), "403"),
+		})
 		return
 	}
 	writeJSON(w, info)

internal/worker/sdk/processor_test.go

@@ -1,9 +1,12 @@
 package sdk
 
 import (
+	"context"
 	"os"
 	"path/filepath"
+	"sync"
 	"testing"
+	"time"
 
 	"github.com/lukaszraczylo/claude-mnemonic/pkg/models"
 	"github.com/stretchr/testify/assert"
@@ -1178,3 +1181,663 @@ func TestSafeResolvePath(t *testing.T) {
 		})
 	}
 }
+
+// =============================================================================
+// TESTS FOR CircuitBreaker
+// =============================================================================
+
+func TestNewCircuitBreaker(t *testing.T) {
+	cb := NewCircuitBreaker(5, 60)
+
+	assert.NotNil(t, cb)
+	assert.Equal(t, int64(5), cb.threshold)
+	assert.Equal(t, int64(60), cb.resetTimeout)
+	assert.Equal(t, "closed", cb.State())
+}
+
+func TestCircuitBreaker_Allow_Closed(t *testing.T) {
+	cb := NewCircuitBreaker(5, 60)
+
+	// Closed state should allow requests
+	assert.True(t, cb.Allow())
+	assert.True(t, cb.Allow())
+}
+
+func TestCircuitBreaker_Allow_Open(t *testing.T) {
+	cb := NewCircuitBreaker(2, 60) // Low threshold for testing
+
+	// Record enough failures to open the circuit
+	cb.RecordFailure()
+	cb.RecordFailure()
+
+	// Open state should block requests
+	assert.False(t, cb.Allow())
+	assert.Equal(t, "open", cb.State())
+}
+
+func TestCircuitBreaker_RecordSuccess(t *testing.T) {
+	cb := NewCircuitBreaker(2, 60)
+
+	// Record a failure
+	cb.RecordFailure()
+	assert.Equal(t, int64(1), cb.Metrics().Failures)
+
+	// Record success resets failures
+	cb.RecordSuccess()
+	assert.Equal(t, int64(0), cb.Metrics().Failures)
+	assert.Equal(t, "closed", cb.State())
+}
+
+func TestCircuitBreaker_RecordFailure_OpensCircuit(t *testing.T) {
+	cb := NewCircuitBreaker(3, 60)
+
+	// Record failures below threshold
+	cb.RecordFailure()
+	assert.Equal(t, "closed", cb.State())
+
+	cb.RecordFailure()
+	assert.Equal(t, "closed", cb.State())
+
+	// Third failure should open circuit
+	cb.RecordFailure()
+	assert.Equal(t, "open", cb.State())
+}
+
+func TestCircuitBreaker_State(t *testing.T) {
+	cb := NewCircuitBreaker(1, 60)
+
+	// Initially closed
+	assert.Equal(t, "closed", cb.State())
+
+	// After failure, open
+	cb.RecordFailure()
+	assert.Equal(t, "open", cb.State())
+
+	// After success, closed
+	cb.RecordSuccess()
+	assert.Equal(t, "closed", cb.State())
+}
+
+func TestCircuitBreaker_Metrics(t *testing.T) {
+	cb := NewCircuitBreaker(5, 120)
+
+	metrics := cb.Metrics()
+	assert.Equal(t, "closed", metrics.State)
+	assert.Equal(t, int64(0), metrics.Failures)
+	assert.Equal(t, int64(5), metrics.Threshold)
+	assert.Equal(t, int64(120), metrics.ResetTimeoutSecs)
+	assert.Equal(t, int64(0), metrics.LastFailureUnix)
+
+	// After failure
+	cb.RecordFailure()
+	metrics = cb.Metrics()
+	assert.Equal(t, int64(1), metrics.Failures)
+	assert.Greater(t, metrics.LastFailureUnix, int64(0))
+}
+
+func TestCircuitBreaker_Metrics_OpenWithReset(t *testing.T) {
+	cb := NewCircuitBreaker(1, 60)
+
+	cb.RecordFailure()
+	assert.Equal(t, "open", cb.State())
+
+	metrics := cb.Metrics()
+	assert.Equal(t, "open", metrics.State)
+	assert.Greater(t, metrics.SecondsUntilReset, int64(0))
+	assert.LessOrEqual(t, metrics.SecondsUntilReset, int64(60))
+}
+
+// =============================================================================
+// TESTS FOR RequestDeduplicator
+// =============================================================================
+
+func TestNewRequestDeduplicator(t *testing.T) {
+	d := NewRequestDeduplicator(300, 1000)
+
+	assert.NotNil(t, d)
+	assert.NotNil(t, d.seen)
+	assert.Equal(t, int64(300), d.ttlSecs)
+	assert.Equal(t, 1000, d.maxSize)
+}
+
+func TestRequestDeduplicator_IsDuplicate_NotSeen(t *testing.T) {
+	d := NewRequestDeduplicator(300, 1000)
+
+	// New hash is not a duplicate
+	assert.False(t, d.IsDuplicate("newhash"))
+}
+
+func TestRequestDeduplicator_IsDuplicate_AfterRecord(t *testing.T) {
+	d := NewRequestDeduplicator(300, 1000)
+
+	hash := "testhash"
+
+	// Record the hash
+	d.Record(hash)
+
+	// Now it should be a duplicate
+	assert.True(t, d.IsDuplicate(hash))
+}
+
+func TestRequestDeduplicator_Record(t *testing.T) {
+	d := NewRequestDeduplicator(300, 1000)
+
+	hash := "recordtest"
+	d.Record(hash)
+
+	// Check it was recorded
+	d.mu.RLock()
+	_, exists := d.seen[hash]
+	d.mu.RUnlock()
+
+	assert.True(t, exists)
+}
+
+func TestRequestDeduplicator_Record_Eviction(t *testing.T) {
+	// Small maxSize for testing eviction
+	d := NewRequestDeduplicator(0, 2) // TTL of 0 means everything is "old"
+
+	// Record until capacity
+	d.Record("hash1")
+	d.Record("hash2")
+
+	// Recording a third should trigger eviction (since TTL is 0)
+	d.Record("hash3")
+
+	// Should have cleaned up old entries
+	d.mu.RLock()
+	size := len(d.seen)
+	d.mu.RUnlock()
+
+	// Size should be limited (eviction occurred)
+	assert.LessOrEqual(t, size, 3)
+}
+
+func TestHashRequest(t *testing.T) {
+	tests := []struct {
+		name        string
+		toolName    string
+		input       string
+		output      string
+		compareWith []string
+		wantLen     int
+		wantSame    bool
+	}{
+		{
+			name:     "basic hash",
+			toolName: "Read",
+			input:    "file.txt",
+			output:   "content",
+			wantLen:  16,
+		},
+		{
+			name:     "consistent hashing",
+			toolName: "Edit",
+			input:    "same input",
+			output:   "same output",
+			wantLen:  16,
+		},
+		{
+			name:     "long output truncation",
+			toolName: "Bash",
+			input:    "command",
+			output:   string(make([]byte, 5000)), // Very long output
+			wantLen:  16,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			hash := hashRequest(tt.toolName, tt.input, tt.output)
+			assert.Len(t, hash, tt.wantLen)
+
+			// Same inputs should produce same hash
+			hash2 := hashRequest(tt.toolName, tt.input, tt.output)
+			assert.Equal(t, hash, hash2)
+		})
+	}
+}
+
+func TestHashRequest_DifferentInputs(t *testing.T) {
+	// Different inputs should produce different hashes
+	hash1 := hashRequest("Read", "file1.txt", "content1")
+	hash2 := hashRequest("Read", "file2.txt", "content2")
+
+	assert.NotEqual(t, hash1, hash2)
+}
+
+func TestHashRequest_OutputTruncation(t *testing.T) {
+	// Hash should be the same for outputs that differ only after 1000 chars
+	longOutput1 := string(make([]byte, 1500))
+	longOutput2 := longOutput1[:1000] + "different suffix here"
+
+	hash1 := hashRequest("Read", "input", longOutput1)
+	hash2 := hashRequest("Read", "input", longOutput2)
+
+	// Since we only hash first 1000 chars, these should be the same
+	assert.Equal(t, hash1, hash2)
+}
+
+// =============================================================================
+// TESTS FOR Processor methods
+// =============================================================================
+
+func TestProcessor_CircuitBreakerState(t *testing.T) {
+	p := &Processor{
+		circuitBreaker: NewCircuitBreaker(2, 60),
+	}
+
+	// Initially closed
+	assert.Equal(t, "closed", p.CircuitBreakerState())
+
+	// After enough failures, open
+	p.circuitBreaker.RecordFailure()
+	p.circuitBreaker.RecordFailure()
+	assert.Equal(t, "open", p.CircuitBreakerState())
+
+	// After success, closed
+	p.circuitBreaker.RecordSuccess()
+	assert.Equal(t, "closed", p.CircuitBreakerState())
+}
+
+func TestProcessor_CircuitBreakerMetrics(t *testing.T) {
+	p := &Processor{
+		circuitBreaker: NewCircuitBreaker(5, 120),
+	}
+
+	metrics := p.CircuitBreakerMetrics()
+	assert.Equal(t, "closed", metrics.State)
+	assert.Equal(t, int64(0), metrics.Failures)
+	assert.Equal(t, int64(5), metrics.Threshold)
+	assert.Equal(t, int64(120), metrics.ResetTimeoutSecs)
+
+	// Record a failure and check metrics update
+	p.circuitBreaker.RecordFailure()
+	metrics = p.CircuitBreakerMetrics()
+	assert.Equal(t, int64(1), metrics.Failures)
+	assert.Greater(t, metrics.LastFailureUnix, int64(0))
+}
+
+// =============================================================================
+// TESTS FOR Vector Sync Workers
+// =============================================================================
+
+func TestProcessor_StartAndStopVectorSyncWorkers(t *testing.T) {
+	var syncedObservations []*models.Observation
+	var mu sync.Mutex
+
+	p := &Processor{
+		vectorSyncChan: make(chan *models.Observation, MaxVectorSyncWorkers*2),
+		vectorSyncDone: make(chan struct{}),
+		syncObservationFunc: func(obs *models.Observation) {
+			mu.Lock()
+			syncedObservations = append(syncedObservations, obs)
+			mu.Unlock()
+		},
+	}
+
+	// Start workers
+	p.StartVectorSyncWorkers()
+
+	// Send some observations
+	obs1 := &models.Observation{SDKSessionID: "test1"}
+	obs2 := &models.Observation{SDKSessionID: "test2"}
+	p.vectorSyncChan <- obs1
+	p.vectorSyncChan <- obs2
+
+	// Give workers time to process
+	time.Sleep(50 * time.Millisecond)
+
+	// Stop workers
+	p.StopVectorSyncWorkers()
+
+	// Verify observations were synced
+	mu.Lock()
+	assert.Len(t, syncedObservations, 2)
+	mu.Unlock()
+}
+
+func TestProcessor_VectorSyncWorker_DrainOnShutdown(t *testing.T) {
+	var syncedCount int
+	var mu sync.Mutex
+
+	p := &Processor{
+		vectorSyncChan: make(chan *models.Observation, 10),
+		vectorSyncDone: make(chan struct{}),
+		syncObservationFunc: func(obs *models.Observation) {
+			mu.Lock()
+			syncedCount++
+			mu.Unlock()
+		},
+	}
+
+	// Queue observations before starting workers
+	for i := 0; i < 5; i++ {
+		p.vectorSyncChan <- &models.Observation{SDKSessionID: "pre-queued"}
+	}
+
+	// Start workers
+	p.StartVectorSyncWorkers()
+
+	// Stop immediately - workers should drain the queue
+	p.StopVectorSyncWorkers()
+
+	// All pre-queued items should have been processed
+	mu.Lock()
+	assert.Equal(t, 5, syncedCount)
+	mu.Unlock()
+}
+
+func TestProcessor_VectorSyncWorker_NilSyncFunc(t *testing.T) {
+	p := &Processor{
+		vectorSyncChan:      make(chan *models.Observation, 10),
+		vectorSyncDone:      make(chan struct{}),
+		syncObservationFunc: nil, // No sync function set
+	}
+
+	// Start workers
+	p.StartVectorSyncWorkers()
+
+	// Send observation - should not panic even with nil sync func
+	p.vectorSyncChan <- &models.Observation{SDKSessionID: "test"}
+
+	// Give it time to process
+	time.Sleep(50 * time.Millisecond)
+
+	// Stop workers - should not panic
+	p.StopVectorSyncWorkers()
+}
+
+// =============================================================================
+// TESTS FOR CircuitBreaker Additional Behaviors
+// =============================================================================
+
+func TestCircuitBreaker_Allow_OpenBlocksRequests(t *testing.T) {
+	cb := NewCircuitBreaker(1, 60)
+
+	// Open the circuit
+	cb.RecordFailure()
+	assert.Equal(t, "open", cb.State())
+
+	// All requests should be blocked
+	assert.False(t, cb.Allow())
+	assert.False(t, cb.Allow())
+	assert.False(t, cb.Allow())
+}
+
+func TestCircuitBreaker_MultipleFailures(t *testing.T) {
+	cb := NewCircuitBreaker(3, 60) // Higher threshold
+
+	// Record failures below threshold
+	cb.RecordFailure()
+	assert.Equal(t, "closed", cb.State())
+	assert.Equal(t, int64(1), cb.Metrics().Failures)
+
+	cb.RecordFailure()
+	assert.Equal(t, "closed", cb.State())
+	assert.Equal(t, int64(2), cb.Metrics().Failures)
+
+	// Third failure opens circuit
+	cb.RecordFailure()
+	assert.Equal(t, "open", cb.State())
+	assert.Equal(t, int64(3), cb.Metrics().Failures)
+}
+
+func TestCircuitBreaker_SuccessResetsFailures(t *testing.T) {
+	cb := NewCircuitBreaker(5, 60)
+
+	// Record some failures
+	cb.RecordFailure()
+	cb.RecordFailure()
+	assert.Equal(t, int64(2), cb.Metrics().Failures)
+
+	// Success resets failures
+	cb.RecordSuccess()
+	assert.Equal(t, int64(0), cb.Metrics().Failures)
+	assert.Equal(t, "closed", cb.State())
+}
+
+func TestCircuitBreaker_Metrics_Comprehensive(t *testing.T) {
+	cb := NewCircuitBreaker(5, 120)
+
+	// Initial state
+	metrics := cb.Metrics()
+	assert.Equal(t, "closed", metrics.State)
+	assert.Equal(t, int64(0), metrics.Failures)
+	assert.Equal(t, int64(5), metrics.Threshold)
+	assert.Equal(t, int64(120), metrics.ResetTimeoutSecs)
+	assert.Equal(t, int64(0), metrics.LastFailureUnix)
+	assert.Equal(t, int64(0), metrics.SecondsUntilReset)
+
+	// After failures that open circuit
+	for i := 0; i < 5; i++ {
+		cb.RecordFailure()
+	}
+	metrics = cb.Metrics()
+	assert.Equal(t, "open", metrics.State)
+	assert.Equal(t, int64(5), metrics.Failures)
+	assert.Greater(t, metrics.LastFailureUnix, int64(0))
+	assert.Greater(t, metrics.SecondsUntilReset, int64(0))
+}
+
+// =============================================================================
+// TESTS FOR MaxVectorSyncWorkers constant
+// =============================================================================
+
+func TestMaxVectorSyncWorkers(t *testing.T) {
+	assert.Equal(t, 8, MaxVectorSyncWorkers)
+}
+
+// =============================================================================
+// ADDITIONAL EDGE CASE TESTS
+// =============================================================================
+
+func TestRequestDeduplicator_IsDuplicate_ExpiredEntry(t *testing.T) {
+	if testing.Short() {
+		t.Skip("Skipping time-dependent test in short mode")
+	}
+	// Use a 1-second TTL with enough margin
+	d := NewRequestDeduplicator(1, 100)
+
+	hash := "expiretest"
+	d.Record(hash)
+
+	// Initially duplicate
+	assert.True(t, d.IsDuplicate(hash))
+
+	// Wait for TTL to expire (2.5 seconds to ensure crossing second boundaries)
+	time.Sleep(2500 * time.Millisecond)
+
+	// Should no longer be considered duplicate
+	assert.False(t, d.IsDuplicate(hash))
+}
+
+// =============================================================================
+// TESTS FOR ProcessObservation Early Returns
+// =============================================================================
+
+func TestProcessObservation_SkipTool(t *testing.T) {
+	p := &Processor{
+		circuitBreaker: NewCircuitBreaker(5, 60),
+		deduplicator:   NewRequestDeduplicator(300, 1000),
+	}
+
+	ctx := context.Background()
+
+	// TodoWrite should be skipped
+	err := p.ProcessObservation(ctx, "session-1", "project-1", "TodoWrite",
+		map[string]string{"content": "test"}, "success", 1, "/test/cwd")
+	assert.NoError(t, err)
+
+	// Glob should be skipped
+	err = p.ProcessObservation(ctx, "session-1", "project-1", "Glob",
+		map[string]string{"pattern": "*.go"}, []string{"main.go", "test.go"}, 1, "/test/cwd")
+	assert.NoError(t, err)
+
+	// AskUserQuestion should be skipped
+	err = p.ProcessObservation(ctx, "session-1", "project-1", "AskUserQuestion",
+		"question", "answer", 1, "/test/cwd")
+	assert.NoError(t, err)
+}
+
+func TestProcessObservation_SkipTrivial(t *testing.T) {
+	p := &Processor{
+		circuitBreaker: NewCircuitBreaker(5, 60),
+		deduplicator:   NewRequestDeduplicator(300, 1000),
+	}
+
+	ctx := context.Background()
+
+	// Short output should be skipped
+	err := p.ProcessObservation(ctx, "session-1", "project-1", "Read",
+		map[string]string{"file_path": "/test.go"}, "short", 1, "/test/cwd")
+	assert.NoError(t, err)
+
+	// "No matches found" should be skipped
+	err = p.ProcessObservation(ctx, "session-1", "project-1", "Grep",
+		map[string]string{"pattern": "test"}, "No matches found in the repository", 1, "/test/cwd")
+	assert.NoError(t, err)
+}
+
+func TestProcessObservation_SkipDuplicate(t *testing.T) {
+	p := &Processor{
+		circuitBreaker: NewCircuitBreaker(5, 60),
+		deduplicator:   NewRequestDeduplicator(300, 1000),
+		sem:            make(chan struct{}, 4),
+		claudePath:     "/nonexistent/path", // Will fail at CLI call stage
+	}
+
+	ctx := context.Background()
+
+	// Valid input that would be processed
+	input := map[string]string{"file_path": "/project/main.go"}
+	output := "package main\n\nimport \"fmt\"\n\nfunc main() {\n\tfmt.Println(\"Hello World\")\n}"
+
+	// First call should try to process (will fail because claudePath doesn't exist)
+	err := p.ProcessObservation(ctx, "session-1", "project-1", "Read", input, output, 1, "/test/cwd")
+	// Expect error because claudePath doesn't exist
+	assert.Error(t, err)
+
+	// Second call with same input should be skipped as duplicate
+	err = p.ProcessObservation(ctx, "session-1", "project-1", "Read", input, output, 1, "/test/cwd")
+	assert.NoError(t, err) // No error because it was skipped as duplicate
+}
+
+func TestProcessObservation_CircuitBreakerOpen(t *testing.T) {
+	cb := NewCircuitBreaker(1, 60) // Threshold of 1
+	cb.RecordFailure()             // Open the circuit breaker
+
+	p := &Processor{
+		circuitBreaker: cb,
+		deduplicator:   NewRequestDeduplicator(300, 1000),
+	}
+
+	ctx := context.Background()
+
+	// Valid input that would be processed
+	input := map[string]string{"file_path": "/project/main.go"}
+	output := "package main\n\nimport \"fmt\"\n\nfunc main() {\n\tfmt.Println(\"Hello World\")\n}"
+
+	err := p.ProcessObservation(ctx, "session-1", "project-1", "Read", input, output, 1, "/test/cwd")
+	assert.Error(t, err)
+	assert.Contains(t, err.Error(), "circuit breaker open")
+}
+
+func TestProcessObservation_ContextCancel(t *testing.T) {
+	p := &Processor{
+		circuitBreaker: NewCircuitBreaker(5, 60),
+		deduplicator:   NewRequestDeduplicator(300, 1000),
+		sem:            make(chan struct{}, 1), // Small semaphore
+		claudePath:     "/fake/claude",
+	}
+
+	// Fill the semaphore
+	p.sem <- struct{}{}
+
+	// Create a cancelled context
+	ctx, cancel := context.WithCancel(context.Background())
+	cancel() // Cancel immediately
+
+	// Valid input that would be processed
+	input := map[string]string{"file_path": "/project/main.go"}
+	output := "package main\n\nimport \"fmt\"\n\nfunc main() {\n\tfmt.Println(\"Hello World\")\n}"
+
+	err := p.ProcessObservation(ctx, "session-1", "project-1", "Read", input, output, 1, "/test/cwd")
+	assert.Error(t, err)
+	assert.ErrorIs(t, err, context.Canceled)
+}
+
+// =============================================================================
+// TESTS FOR ProcessSummary Early Returns
+// =============================================================================
+
+func TestProcessSummary_SkipEmptyRequest(t *testing.T) {
+	p := &Processor{
+		circuitBreaker: NewCircuitBreaker(5, 60),
+		deduplicator:   NewRequestDeduplicator(300, 1000),
+	}
+
+	ctx := context.Background()
+
+	// Empty request should be skipped (sessionDBID, sdkSessionID, project, userPrompt, lastUserMsg, lastAssistantMsg)
+	err := p.ProcessSummary(ctx, 1, "session-1", "project-1", "", "", "")
+	assert.NoError(t, err)
+}
+
+func TestProcessSummary_CircuitBreakerOpen(t *testing.T) {
+	cb := NewCircuitBreaker(1, 60)
+	cb.RecordFailure() // Open the circuit breaker
+
+	p := &Processor{
+		circuitBreaker: cb,
+		deduplicator:   NewRequestDeduplicator(300, 1000),
+		sem:            make(chan struct{}, 4),
+		claudePath:     "/nonexistent/path",
+	}
+
+	ctx := context.Background()
+
+	// Meaningful assistant message (> 200 chars, contains code discussion)
+	assistantMsg := `I've updated the handler.go file to fix the authentication bug.
+The function validateToken() was not checking token expiry correctly.
+I've added a check for the exp claim and implemented proper error handling.
+The changes have been tested and the build passes successfully.
+Here's the implementation details and code review.`
+
+	// Valid request but circuit breaker is open
+	err := p.ProcessSummary(ctx, 1, "session-1", "project-1",
+		"Implement authentication", "User message", assistantMsg)
+	assert.Error(t, err)
+	assert.Contains(t, err.Error(), "claude CLI failed")
+}
+
+// =============================================================================
+// TESTS FOR callClaudeCLI Error Paths
+// =============================================================================
+
+func TestCallClaudeCLI_PromptTooLarge(t *testing.T) {
+	p := &Processor{
+		claudePath: "/fake/claude",
+	}
+
+	ctx := context.Background()
+
+	// Create a prompt that exceeds MaxPromptSize
+	largePrompt := string(make([]byte, MaxPromptSize+1))
+
+	_, err := p.callClaudeCLI(ctx, largePrompt)
+	assert.Error(t, err)
+	assert.Contains(t, err.Error(), "prompt exceeds maximum size")
+}
+
+func TestCallClaudeCLI_BinaryNotFound(t *testing.T) {
+	p := &Processor{
+		claudePath: "/nonexistent/path/to/claude",
+	}
+
+	ctx := context.Background()
+
+	_, err := p.callClaudeCLI(ctx, "test prompt")
+	assert.Error(t, err)
+	assert.Contains(t, err.Error(), "claude CLI failed")
+}

internal/worker/service.go

@@ -1198,6 +1198,8 @@ func (s *Service) setupRoutes() {
 	// Vector management endpoints
 	s.router.Post("/api/vectors/rebuild", s.handleTriggerVectorRebuild)
 	s.router.Get("/api/vectors/health", s.handleVectorHealth)
+	s.router.Get("/api/vector/metrics", s.handleVectorMetrics)
+	s.router.Get("/api/graph/stats", s.handleGraphStats)
 
 	// Readiness check - returns 200 only when fully initialized
 	s.router.Get("/api/ready", s.handleReady)

internal/worker/session/manager_test.go

@@ -693,3 +693,734 @@ func TestToolInputResponse(t *testing.T) {
 		})
 	}
 }
+
+// =============================================================================
+// TESTS FOR NewManager AND CLEANUP
+// =============================================================================
+
+// TestNewManager tests the NewManager function.
+func TestNewManager(t *testing.T) {
+	t.Parallel()
+
+	// Test with nil session store (valid for testing)
+	manager := NewManager(nil)
+
+	assert.NotNil(t, manager)
+	assert.NotNil(t, manager.sessions)
+	assert.NotNil(t, manager.ProcessNotify)
+	assert.NotNil(t, manager.ctx)
+	assert.NotNil(t, manager.cancel)
+	assert.Equal(t, 0, manager.GetActiveSessionCount())
+
+	// Clean up - cancel context to stop cleanup goroutine
+	manager.cancel()
+}
+
+// TestNewManager_CleanupGoroutineStops tests that cleanup goroutine stops on cancel.
+func TestNewManager_CleanupGoroutineStops(t *testing.T) {
+	t.Parallel()
+
+	manager := NewManager(nil)
+
+	// Give goroutine time to start
+	time.Sleep(10 * time.Millisecond)
+
+	// Cancel should stop the cleanup goroutine
+	manager.cancel()
+
+	// Context should be done
+	select {
+	case <-manager.ctx.Done():
+		// Expected
+	case <-time.After(100 * time.Millisecond):
+		t.Error("Context should be done after cancel")
+	}
+}
+
+// TestCleanupStaleSessions_NoSessions tests cleanup with no sessions.
+func TestCleanupStaleSessions_NoSessions(t *testing.T) {
+	t.Parallel()
+
+	manager := &Manager{
+		sessions:      make(map[int64]*ActiveSession),
+		ProcessNotify: make(chan struct{}, 1),
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	manager.ctx = ctx
+	manager.cancel = cancel
+
+	// Should not panic with empty sessions
+	manager.cleanupStaleSessions()
+	assert.Equal(t, 0, manager.GetActiveSessionCount())
+}
+
+// TestCleanupStaleSessions_FreshSession tests that fresh sessions are not cleaned.
+func TestCleanupStaleSessions_FreshSession(t *testing.T) {
+	t.Parallel()
+
+	manager := &Manager{
+		sessions:      make(map[int64]*ActiveSession),
+		ProcessNotify: make(chan struct{}, 1),
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	manager.ctx = ctx
+	manager.cancel = cancel
+
+	// Add a fresh session
+	sessionCtx, sessionCancel := context.WithCancel(context.Background())
+	manager.sessions[1] = &ActiveSession{
+		SessionDBID:     1,
+		StartTime:       time.Now(), // Fresh
+		pendingMessages: []PendingMessage{},
+		ctx:             sessionCtx,
+		cancel:          sessionCancel,
+	}
+
+	manager.cleanupStaleSessions()
+
+	// Session should still exist (not stale)
+	assert.Equal(t, 1, manager.GetActiveSessionCount())
+	sessionCancel()
+}
+
+// TestCleanupStaleSessions_StaleSession tests that stale sessions are cleaned.
+func TestCleanupStaleSessions_StaleSession(t *testing.T) {
+	t.Parallel()
+
+	manager := &Manager{
+		sessions:      make(map[int64]*ActiveSession),
+		ProcessNotify: make(chan struct{}, 1),
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	manager.ctx = ctx
+	manager.cancel = cancel
+
+	// Add a stale session
+	sessionCtx, sessionCancel := context.WithCancel(context.Background())
+	manager.sessions[1] = &ActiveSession{
+		SessionDBID:     1,
+		StartTime:       time.Now().Add(-SessionTimeout - time.Minute), // Stale
+		pendingMessages: []PendingMessage{},
+		ctx:             sessionCtx,
+		cancel:          sessionCancel,
+	}
+
+	manager.cleanupStaleSessions()
+
+	// Session should be deleted
+	assert.Equal(t, 0, manager.GetActiveSessionCount())
+}
+
+// TestCleanupStaleSessions_StaleWithPending tests stale sessions with pending messages are not cleaned.
+func TestCleanupStaleSessions_StaleWithPending(t *testing.T) {
+	t.Parallel()
+
+	manager := &Manager{
+		sessions:      make(map[int64]*ActiveSession),
+		ProcessNotify: make(chan struct{}, 1),
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	manager.ctx = ctx
+	manager.cancel = cancel
+
+	// Add a stale session with pending messages
+	sessionCtx, sessionCancel := context.WithCancel(context.Background())
+	defer sessionCancel()
+	manager.sessions[1] = &ActiveSession{
+		SessionDBID:     1,
+		StartTime:       time.Now().Add(-SessionTimeout - time.Minute), // Stale
+		pendingMessages: []PendingMessage{{Type: MessageTypeObservation}},
+		ctx:             sessionCtx,
+		cancel:          sessionCancel,
+	}
+
+	manager.cleanupStaleSessions()
+
+	// Session should NOT be deleted (has pending messages)
+	assert.Equal(t, 1, manager.GetActiveSessionCount())
+}
+
+// TestCleanupStaleSessions_StaleWithActiveGenerator tests stale sessions with active generator are not cleaned.
+func TestCleanupStaleSessions_StaleWithActiveGenerator(t *testing.T) {
+	t.Parallel()
+
+	manager := &Manager{
+		sessions:      make(map[int64]*ActiveSession),
+		ProcessNotify: make(chan struct{}, 1),
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	manager.ctx = ctx
+	manager.cancel = cancel
+
+	// Add a stale session with active generator
+	sessionCtx, sessionCancel := context.WithCancel(context.Background())
+	defer sessionCancel()
+	session := &ActiveSession{
+		SessionDBID:     1,
+		StartTime:       time.Now().Add(-SessionTimeout - time.Minute), // Stale
+		pendingMessages: []PendingMessage{},
+		ctx:             sessionCtx,
+		cancel:          sessionCancel,
+	}
+	session.generatorActive.Store(true)
+	manager.sessions[1] = session
+
+	manager.cleanupStaleSessions()
+
+	// Session should NOT be deleted (generator is active)
+	assert.Equal(t, 1, manager.GetActiveSessionCount())
+}
+
+// TestCleanupStaleSessions_MixedSessions tests cleanup with mixed fresh and stale sessions.
+func TestCleanupStaleSessions_MixedSessions(t *testing.T) {
+	t.Parallel()
+
+	manager := &Manager{
+		sessions:      make(map[int64]*ActiveSession),
+		ProcessNotify: make(chan struct{}, 1),
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	manager.ctx = ctx
+	manager.cancel = cancel
+
+	// Fresh session
+	ctx1, cancel1 := context.WithCancel(context.Background())
+	defer cancel1()
+	manager.sessions[1] = &ActiveSession{
+		SessionDBID:     1,
+		StartTime:       time.Now(),
+		pendingMessages: []PendingMessage{},
+		ctx:             ctx1,
+		cancel:          cancel1,
+	}
+
+	// Stale session (should be deleted)
+	ctx2, cancel2 := context.WithCancel(context.Background())
+	manager.sessions[2] = &ActiveSession{
+		SessionDBID:     2,
+		StartTime:       time.Now().Add(-SessionTimeout - time.Minute),
+		pendingMessages: []PendingMessage{},
+		ctx:             ctx2,
+		cancel:          cancel2,
+	}
+
+	// Stale session with pending (should NOT be deleted)
+	ctx3, cancel3 := context.WithCancel(context.Background())
+	defer cancel3()
+	manager.sessions[3] = &ActiveSession{
+		SessionDBID:     3,
+		StartTime:       time.Now().Add(-SessionTimeout - time.Minute),
+		pendingMessages: []PendingMessage{{Type: MessageTypeObservation}},
+		ctx:             ctx3,
+		cancel:          cancel3,
+	}
+
+	manager.cleanupStaleSessions()
+
+	// Should have 2 sessions left (1 fresh, 1 stale with pending)
+	assert.Equal(t, 2, manager.GetActiveSessionCount())
+
+	// Verify which sessions remain
+	manager.mu.RLock()
+	_, has1 := manager.sessions[1]
+	_, has2 := manager.sessions[2]
+	_, has3 := manager.sessions[3]
+	manager.mu.RUnlock()
+
+	assert.True(t, has1, "Fresh session should remain")
+	assert.False(t, has2, "Stale session should be deleted")
+	assert.True(t, has3, "Stale session with pending should remain")
+}
+
+// TestCleanupLoop_ExitsOnCancel tests that cleanup loop exits when context is cancelled.
+func TestCleanupLoop_ExitsOnCancel(t *testing.T) {
+	t.Parallel()
+
+	manager := &Manager{
+		sessions:      make(map[int64]*ActiveSession),
+		ProcessNotify: make(chan struct{}, 1),
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	manager.ctx = ctx
+	manager.cancel = cancel
+
+	// Start cleanup loop in goroutine
+	done := make(chan struct{})
+	go func() {
+		manager.cleanupLoop()
+		close(done)
+	}()
+
+	// Cancel immediately
+	cancel()
+
+	// Should exit quickly
+	select {
+	case <-done:
+		// Success - loop exited
+	case <-time.After(100 * time.Millisecond):
+		t.Error("Cleanup loop should exit when context is cancelled")
+	}
+}
+
+// =============================================================================
+// TESTS FOR InitializeSession (without DB)
+// =============================================================================
+
+// TestInitializeSession_AlreadyActive tests reusing an already active session.
+func TestInitializeSession_AlreadyActive(t *testing.T) {
+	t.Parallel()
+
+	manager := &Manager{
+		sessions:      make(map[int64]*ActiveSession),
+		ProcessNotify: make(chan struct{}, 1),
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	manager.ctx = ctx
+	manager.cancel = cancel
+
+	// Pre-add an active session
+	existingSession := &ActiveSession{
+		SessionDBID:      42,
+		ClaudeSessionID:  "claude-existing",
+		Project:          "test-project",
+		UserPrompt:       "original prompt",
+		LastPromptNumber: 1,
+		StartTime:        time.Now(),
+		pendingMessages:  make([]PendingMessage, 0),
+	}
+	manager.sessions[42] = existingSession
+
+	// Initialize same session - should reuse
+	session, err := manager.InitializeSession(context.Background(), 42, "new prompt", 5)
+
+	assert.NoError(t, err)
+	assert.NotNil(t, session)
+	assert.Same(t, existingSession, session)
+	assert.Equal(t, "new prompt", session.UserPrompt)
+	assert.Equal(t, 5, session.LastPromptNumber)
+}
+
+// TestInitializeSession_AlreadyActive_EmptyPrompt tests reusing session with empty prompt.
+func TestInitializeSession_AlreadyActive_EmptyPrompt(t *testing.T) {
+	t.Parallel()
+
+	manager := &Manager{
+		sessions:      make(map[int64]*ActiveSession),
+		ProcessNotify: make(chan struct{}, 1),
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	manager.ctx = ctx
+	manager.cancel = cancel
+
+	// Pre-add an active session
+	existingSession := &ActiveSession{
+		SessionDBID:      42,
+		UserPrompt:       "original prompt",
+		LastPromptNumber: 1,
+	}
+	manager.sessions[42] = existingSession
+
+	// Initialize with empty prompt - should NOT update
+	session, err := manager.InitializeSession(context.Background(), 42, "", 0)
+
+	assert.NoError(t, err)
+	assert.NotNil(t, session)
+	assert.Equal(t, "original prompt", session.UserPrompt) // Unchanged
+	assert.Equal(t, 1, session.LastPromptNumber)           // Unchanged
+}
+
+// TestInitializeSession_NoStore tests initialization without session store.
+func TestInitializeSession_NoStore(t *testing.T) {
+	t.Parallel()
+
+	manager := &Manager{
+		sessionStore:  nil, // No store
+		sessions:      make(map[int64]*ActiveSession),
+		ProcessNotify: make(chan struct{}, 1),
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	manager.ctx = ctx
+	manager.cancel = cancel
+
+	// Should fail gracefully with nil store (panic recovery not expected)
+	// This tests the guard against nil sessionStore
+	defer func() {
+		if r := recover(); r != nil {
+			_ = r // Expected panic when calling nil store - intentionally ignored
+		}
+	}()
+
+	_, _ = manager.InitializeSession(context.Background(), 999, "prompt", 1)
+}
+
+// TestInitializeSession_CallbackTriggered tests that created callback is triggered.
+func TestInitializeSession_CallbackTriggered(t *testing.T) {
+	t.Parallel()
+
+	manager := &Manager{
+		sessions:      make(map[int64]*ActiveSession),
+		ProcessNotify: make(chan struct{}, 1),
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	manager.ctx = ctx
+	manager.cancel = cancel
+
+	var calledWithID int64
+	manager.SetOnSessionCreated(func(id int64) {
+		calledWithID = id
+	})
+
+	// Add session directly (simulating what would happen after DB fetch)
+	sessionCtx, sessionCancel := context.WithCancel(context.Background())
+	defer sessionCancel()
+	session := &ActiveSession{
+		SessionDBID:     100,
+		ClaudeSessionID: "test",
+		Project:         "project",
+		StartTime:       time.Now(),
+		pendingMessages: make([]PendingMessage, 0),
+		notify:          make(chan struct{}, 1),
+		ctx:             sessionCtx,
+		cancel:          sessionCancel,
+	}
+
+	manager.mu.Lock()
+	manager.sessions[100] = session
+	onCreated := manager.onCreated
+	manager.mu.Unlock()
+
+	// Trigger callback
+	if onCreated != nil {
+		onCreated(100)
+	}
+
+	assert.Equal(t, int64(100), calledWithID)
+}
+
+// =============================================================================
+// TESTS FOR QueueObservation AND QueueSummarize (without DB)
+// =============================================================================
+
+// TestQueueObservation_ToExistingSession tests queuing to an existing session.
+func TestQueueObservation_ToExistingSession(t *testing.T) {
+	t.Parallel()
+
+	manager := &Manager{
+		sessions:      make(map[int64]*ActiveSession),
+		ProcessNotify: make(chan struct{}, 1),
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	manager.ctx = ctx
+	manager.cancel = cancel
+
+	// Pre-add session
+	session := &ActiveSession{
+		SessionDBID:     1,
+		pendingMessages: make([]PendingMessage, 0),
+		notify:          make(chan struct{}, 1),
+	}
+	manager.sessions[1] = session
+
+	// Queue observation
+	err := manager.QueueObservation(context.Background(), 1, ObservationData{
+		ToolName:     "Read",
+		ToolInput:    map[string]string{"path": "/test"},
+		ToolResponse: "content",
+		PromptNumber: 1,
+		CWD:          "/project",
+	})
+
+	assert.NoError(t, err)
+	assert.Equal(t, 1, manager.GetTotalQueueDepth())
+
+	// Verify message
+	messages := manager.DrainMessages(1)
+	assert.Len(t, messages, 1)
+	assert.Equal(t, MessageTypeObservation, messages[0].Type)
+	assert.Equal(t, "Read", messages[0].Observation.ToolName)
+	assert.Equal(t, "/project", messages[0].Observation.CWD)
+}
+
+// TestQueueObservation_NotifiesSession tests that notification is sent to session.
+func TestQueueObservation_NotifiesSession(t *testing.T) {
+	t.Parallel()
+
+	manager := &Manager{
+		sessions:      make(map[int64]*ActiveSession),
+		ProcessNotify: make(chan struct{}, 1),
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	manager.ctx = ctx
+	manager.cancel = cancel
+
+	// Pre-add session with notify channel
+	session := &ActiveSession{
+		SessionDBID:     1,
+		pendingMessages: make([]PendingMessage, 0),
+		notify:          make(chan struct{}, 1),
+	}
+	manager.sessions[1] = session
+
+	// Queue observation
+	err := manager.QueueObservation(context.Background(), 1, ObservationData{ToolName: "Test"})
+	assert.NoError(t, err)
+
+	// Should receive notification on session channel
+	select {
+	case <-session.notify:
+		// Success
+	default:
+		t.Error("Session should receive notification")
+	}
+
+	// Should receive notification on process channel
+	select {
+	case <-manager.ProcessNotify:
+		// Success
+	default:
+		t.Error("Manager ProcessNotify should receive notification")
+	}
+}
+
+// TestQueueSummarize_ToExistingSession tests queuing summarize to an existing session.
+func TestQueueSummarize_ToExistingSession(t *testing.T) {
+	t.Parallel()
+
+	manager := &Manager{
+		sessions:      make(map[int64]*ActiveSession),
+		ProcessNotify: make(chan struct{}, 1),
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	manager.ctx = ctx
+	manager.cancel = cancel
+
+	// Pre-add session
+	session := &ActiveSession{
+		SessionDBID:     1,
+		pendingMessages: make([]PendingMessage, 0),
+		notify:          make(chan struct{}, 1),
+	}
+	manager.sessions[1] = session
+
+	// Queue summarize
+	err := manager.QueueSummarize(context.Background(), 1, "User asked question", "Assistant answered")
+	assert.NoError(t, err)
+	assert.Equal(t, 1, manager.GetTotalQueueDepth())
+
+	// Verify message
+	messages := manager.DrainMessages(1)
+	assert.Len(t, messages, 1)
+	assert.Equal(t, MessageTypeSummarize, messages[0].Type)
+	assert.Equal(t, "User asked question", messages[0].Summarize.LastUserMessage)
+	assert.Equal(t, "Assistant answered", messages[0].Summarize.LastAssistantMessage)
+}
+
+// TestQueueSummarize_NotifiesSession tests that notification is sent to session.
+func TestQueueSummarize_NotifiesSession(t *testing.T) {
+	t.Parallel()
+
+	manager := &Manager{
+		sessions:      make(map[int64]*ActiveSession),
+		ProcessNotify: make(chan struct{}, 1),
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	manager.ctx = ctx
+	manager.cancel = cancel
+
+	// Pre-add session with notify channel
+	session := &ActiveSession{
+		SessionDBID:     1,
+		pendingMessages: make([]PendingMessage, 0),
+		notify:          make(chan struct{}, 1),
+	}
+	manager.sessions[1] = session
+
+	// Queue summarize
+	err := manager.QueueSummarize(context.Background(), 1, "user", "assistant")
+	assert.NoError(t, err)
+
+	// Should receive notification on session channel
+	select {
+	case <-session.notify:
+		// Success
+	default:
+		t.Error("Session should receive notification")
+	}
+
+	// Should receive notification on process channel
+	select {
+	case <-manager.ProcessNotify:
+		// Success
+	default:
+		t.Error("Manager ProcessNotify should receive notification")
+	}
+}
+
+// TestQueueOperations_MultipleMessages tests queuing multiple messages.
+func TestQueueOperations_MultipleMessages(t *testing.T) {
+	t.Parallel()
+
+	manager := &Manager{
+		sessions:      make(map[int64]*ActiveSession),
+		ProcessNotify: make(chan struct{}, 1),
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	manager.ctx = ctx
+	manager.cancel = cancel
+
+	// Pre-add session
+	session := &ActiveSession{
+		SessionDBID:     1,
+		pendingMessages: make([]PendingMessage, 0),
+		notify:          make(chan struct{}, 1),
+	}
+	manager.sessions[1] = session
+
+	// Queue multiple messages
+	for i := 0; i < 10; i++ {
+		if i%2 == 0 {
+			err := manager.QueueObservation(context.Background(), 1, ObservationData{
+				ToolName: "Tool" + string(rune('A'+i)),
+			})
+			assert.NoError(t, err)
+		} else {
+			err := manager.QueueSummarize(context.Background(), 1, "user", "assistant")
+			assert.NoError(t, err)
+		}
+	}
+
+	assert.Equal(t, 10, manager.GetTotalQueueDepth())
+
+	// Drain and verify
+	messages := manager.DrainMessages(1)
+	assert.Len(t, messages, 10)
+}
+
+// TestQueueOperations_NonBlockingNotification tests non-blocking notification behavior.
+func TestQueueOperations_NonBlockingNotification(t *testing.T) {
+	t.Parallel()
+
+	manager := &Manager{
+		sessions:      make(map[int64]*ActiveSession),
+		ProcessNotify: make(chan struct{}, 1),
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	manager.ctx = ctx
+	manager.cancel = cancel
+
+	// Pre-add session with full notify channel
+	session := &ActiveSession{
+		SessionDBID:     1,
+		pendingMessages: make([]PendingMessage, 0),
+		notify:          make(chan struct{}, 1),
+	}
+	// Fill the notify channel
+	session.notify <- struct{}{}
+	manager.sessions[1] = session
+
+	// Fill ProcessNotify channel
+	manager.ProcessNotify <- struct{}{}
+
+	// Queue should NOT block even with full channels
+	done := make(chan bool)
+	go func() {
+		err := manager.QueueObservation(context.Background(), 1, ObservationData{ToolName: "Test"})
+		assert.NoError(t, err)
+		done <- true
+	}()
+
+	select {
+	case <-done:
+		// Success - didn't block
+	case <-time.After(100 * time.Millisecond):
+		t.Error("Queue operation should not block even with full notification channels")
+	}
+}
+
+// TestConcurrentQueueAndCleanup tests concurrent queue operations and cleanup.
+func TestConcurrentQueueAndCleanup(t *testing.T) {
+	t.Parallel()
+
+	manager := &Manager{
+		sessions:      make(map[int64]*ActiveSession),
+		ProcessNotify: make(chan struct{}, 1),
+	}
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	manager.ctx = ctx
+	manager.cancel = cancel
+
+	// Pre-add multiple sessions
+	for i := int64(1); i <= 5; i++ {
+		sessionCtx, sessionCancel := context.WithCancel(context.Background())
+		manager.sessions[i] = &ActiveSession{
+			SessionDBID:     i,
+			StartTime:       time.Now(),
+			pendingMessages: make([]PendingMessage, 0),
+			notify:          make(chan struct{}, 1),
+			ctx:             sessionCtx,
+			cancel:          sessionCancel,
+		}
+	}
+
+	var wg sync.WaitGroup
+
+	// Concurrent queue operations
+	for i := 0; i < 50; i++ {
+		wg.Add(1)
+		go func(idx int) {
+			defer wg.Done()
+			sessionID := int64((idx % 5) + 1)
+			if idx%2 == 0 {
+				_ = manager.QueueObservation(context.Background(), sessionID, ObservationData{ToolName: "Test"})
+			} else {
+				_ = manager.QueueSummarize(context.Background(), sessionID, "user", "assistant")
+			}
+		}(i)
+	}
+
+	// Concurrent cleanup
+	for i := 0; i < 10; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			manager.cleanupStaleSessions()
+		}()
+	}
+
+	// Concurrent reads
+	for i := 0; i < 20; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			_ = manager.GetActiveSessionCount()
+			_ = manager.GetTotalQueueDepth()
+			_ = manager.IsAnySessionProcessing()
+			_ = manager.GetAllSessions()
+		}()
+	}
+
+	wg.Wait()
+
+	// Should have all sessions (none are stale)
+	assert.Equal(t, 5, manager.GetActiveSessionCount())
+	// Should have 50 messages total
+	assert.Equal(t, 50, manager.GetTotalQueueDepth())
+}