feat(chunking): add AST-aware code chunking for Go, Python, TypeScript

- [x] Add language-specific chunkers with AST parsing (Go, Python, TypeScript)
- [x] Implement chunking manager to dispatch files to appropriate chunkers
- [x] Integrate code chunks into vector sync for semantic search
- [x] Add tree-sitter dependency for Python/TypeScript parsing
- [x] Reorder struct fields for consistency across codebase
- [x] Rename error variables to follow Go conventions (err → unmarshalErr, etc.)
- [x] Add code chunk metadata to vector documents (language, symbol name, line ranges)
- [x] Update worker service to initialize chunking pipeline with all three languages

cmd/hooks/stop/main.go

@@ -14,17 +14,17 @@ import (
 // Input is the hook input from Claude Code.
 type Input struct {
 	hooks.BaseInput
-	StopHookActive bool   `json:"stop_hook_active"`
 	TranscriptPath string `json:"transcript_path"`
+	StopHookActive bool   `json:"stop_hook_active"`
 }
 
 // TranscriptMessage represents a message in the transcript JSONL file.
 type TranscriptMessage struct {
-	Type    string `json:"type"`
 	Message struct {
+		Content any    `json:"content"`
 		Role    string `json:"role"`
-		Content any    `json:"content"` // Can be string or array
 	} `json:"message"`
+	Type string `json:"type"` // Can be string or array
 }
 
 // extractTextContent extracts text content from message content (handles both string and array formats).