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

internal/vector/sqlitevec/helpers_test.go

@@ -42,10 +42,10 @@ func TestQueryResult_Fields(t *testing.T) {
 
 func TestBuildWhereFilter(t *testing.T) {
 	tests := []struct {
+		expected map[string]interface{}
 		name     string
 		docType  DocType
 		project  string
-		expected map[string]interface{}
 	}{
 		{
 			name:     "empty_filters",
@@ -474,9 +474,9 @@ func TestCopyMetadataMulti(t *testing.T) {
 func TestJoinStrings(t *testing.T) {
 	tests := []struct {
 		name     string
-		strs     []string
 		sep      string
 		expected string
+		strs     []string
 	}{
 		{
 			name:     "empty_slice",
@@ -522,8 +522,8 @@ func TestTruncateString(t *testing.T) {
 	tests := []struct {
 		name     string
 		input    string
-		maxLen   int
 		expected string
+		maxLen   int
 	}{
 		{
 			name:     "shorter_than_max",