feat(leann-phase2): implement hybrid vector storage and graph-based search

- [x] Add AST-aware code chunking for Go, Python, and TypeScript using tree-sitter
- [x] Implement LEANN-inspired hybrid vector storage with hub detection and selective embedding storage (60-80% savings)
- [x] Add observation relationship graph with CSR format and edge detection (file overlap, semantic similarity, temporal, concept)
- [x] Implement graph-aware search with two-level traversal and relationship-based ranking
- [x] Add auto-tuning system for dynamic hub threshold adjustment based on query performance
- [x] Add comprehensive metrics tracking for vector storage, queries, latency, and graph traversals
- [x] Update configuration system with graph and hybrid storage settings
- [x] Add graph stats and vector metrics endpoints to worker service
- [x] Enhance UI sidebar with advanced metrics display and graph visualization
- [x] Optimize struct field alignment throughout codebase for memory efficiency
- [x] Update documentation with LEANN Phase 2 features and performance benefits
- [x] Add tree-sitter dependency for AST parsing

pkg/models/relation_test.go

@@ -8,12 +8,12 @@ import (
 
 func TestDetectFileOverlapRelation(t *testing.T) {
 	tests := []struct {
-		name          string
 		newer         *Observation
 		older         *Observation
-		wantRelation  bool
+		name          string
 		wantRelType   RelationType
 		wantMinConfid float64
+		wantRelation  bool
 	}{
 		{
 			name: "no file overlap",
@@ -105,11 +105,11 @@ func TestDetectFileOverlapRelation(t *testing.T) {
 
 func TestDetectConceptOverlapRelation(t *testing.T) {
 	tests := []struct {
-		name          string
 		newer         *Observation
 		older         *Observation
-		wantRelation  bool
+		name          string
 		wantMinConfid float64
+		wantRelation  bool
 	}{
 		{
 			name: "no concept overlap",
@@ -179,8 +179,8 @@ func TestDetectTypeProgressionRelation(t *testing.T) {
 		name         string
 		newerType    ObservationType
 		olderType    ObservationType
-		wantRelation bool
 		wantRelType  RelationType
+		wantRelation bool
 	}{
 		{
 			name:         "bugfix fixes discovery",
@@ -314,8 +314,8 @@ func TestDetectNarrativeMentionRelation(t *testing.T) {
 	tests := []struct {
 		name         string
 		narrative    string
-		wantRelation bool
 		wantRelType  RelationType
+		wantRelation bool
 	}{
 		{
 			name:         "fixes language",