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

internal/vector/sqlitevec/client.go

@@ -319,11 +319,11 @@ func (c *Client) NeedsRebuild(ctx context.Context) (bool, string) {
 // StaleVectorInfo contains information about a vector that needs rebuilding.
 type StaleVectorInfo struct {
 	DocID     string
-	SQLiteID  int64
 	DocType   string
 	FieldType string
 	Project   string
 	Scope     string
+	SQLiteID  int64
 }
 
 // GetStaleVectors returns doc_ids of vectors with mismatched or null model versions.