feat: replace regex parsers with tree-sitter AST parsing

Replace all regex-based parsers (TypeScript, Python, Rust, Java) with
tree-sitter AST parsers using gotreesitter pure Go runtime. Add new
parsers for C#, Ruby, PHP, Kotlin, Swift, and C/C++.

- 10 language extractors with full import/export/type extraction
- Pure Go, no CGO -- cross-compiles to all platforms
- 205 embedded grammars via gotreesitter
- Delete old regex parsers (typescript.go, python.go, rust.go, java.go)
- All existing tests updated and passing

Author: thegdsks

DEPENDENCIES.md

@@ -4,29 +4,29 @@
 
 ```mermaid
 graph LR
-  classDef typescript fill:#c9d1d9,color:#0d1117,stroke:#c9d1d9
-  classDef python fill:#b1bac4,color:#0d1117,stroke:#b1bac4
   classDef rust fill:#a5b3bf,color:#0d1117,stroke:#a5b3bf
   classDef go fill:#e6edf3,color:#0d1117,stroke:#e6edf3
   classDef javascript fill:#c9d1d9,color:#0d1117,stroke:#c9d1d9
   classDef java fill:#8b949e,color:#0d1117,stroke:#8b949e
+  classDef typescript fill:#c9d1d9,color:#0d1117,stroke:#c9d1d9
+  classDef python fill:#b1bac4,color:#0d1117,stroke:#b1bac4
+  internal_summary["internal/summary<br/>AI-powered codebase summaries"]:::go
+  internal_detect["internal/detect<br/>Framework and tool detection"]:::go
   internal_engine["internal/engine<br/>Core orchestration engine"]:::go
-  internal_parser["internal/parser<br/>Source code parsers"]:::go
-  npm_bin["npm/bin<br/>Bin"]:::go
-  internal_cli["internal/cli<br/>Command-line interface"]:::go
-  internal_monorepo["internal/monorepo<br/>Monorepo detection"]:::go
-  internal_renderer["internal/renderer<br/>Output renderers"]:::go
+  internal_git["internal/git<br/>Git integration"]:::go
   cmd_stacklit["cmd/stacklit<br/>Stacklit"]:::go
-  internal_summary["internal/summary<br/>AI-powered codebase summaries"]:::go
+  internal_cli["internal/cli<br/>Command-line interface"]:::go
+  internal_mcp["internal/mcp<br/>MCP server for AI agents"]:::go
+  npm_bin["npm/bin<br/>Bin"]:::go
   assets["assets<br/>Static assets"]:::go
-  internal_git["internal/git<br/>Git integration"]:::go
+  internal_config["internal/config<br/>Configuration management"]:::go
   internal_graph["internal/graph<br/>Dependency graph"]:::go
-  internal_mcp["internal/mcp<br/>MCP server for AI agents"]:::go
+  internal_monorepo["internal/monorepo<br/>Monorepo detection"]:::go
+  internal_renderer["internal/renderer<br/>Output renderers"]:::go
+  npm["npm<br/>Npm"]:::go
+  internal_parser["internal/parser<br/>Source code parsers"]:::go
   internal_schema["internal/schema<br/>Data schema definitions"]:::go
   internal_walker["internal/walker<br/>File system walker"]:::go
-  npm["npm<br/>Npm"]:::go
-  internal_config["internal/config<br/>Configuration management"]:::go
-  internal_detect["internal/detect<br/>Framework and tool detection"]:::go
   cmd_stacklit --> internal_cli
   internal_cli --> internal_engine
   internal_cli --> internal_git

go.mod

@@ -11,6 +11,7 @@ require (
 require (
 	github.com/google/jsonschema-go v0.4.2 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
+	github.com/odvcencio/gotreesitter v0.13.4 // indirect
 	github.com/segmentio/asm v1.1.3 // indirect
 	github.com/segmentio/encoding v0.5.4 // indirect
 	github.com/spf13/pflag v1.0.9 // indirect

go.sum

@@ -11,6 +11,8 @@ github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2
 github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
 github.com/modelcontextprotocol/go-sdk v1.5.0 h1:CHU0FIX9kpueNkxuYtfYQn1Z0slhFzBZuq+x6IiblIU=
 github.com/modelcontextprotocol/go-sdk v1.5.0/go.mod h1:gggDIhoemhWs3BGkGwd1umzEXCEMMvAnhTrnbXJKKKA=
+github.com/odvcencio/gotreesitter v0.13.4 h1:O/FqOlabRz1Neg6UISx0URtwuN1FQ2eGCc846KHcBbQ=
+github.com/odvcencio/gotreesitter v0.13.4/go.mod h1:Sx+iYJBfw5xSWkSttLSuFvguJctlH+ma1BTxZ0MPCqo=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=

internal/parser/java.go

@@ -5,30 +5,9 @@ import (
 	"testing"
 )
 
-func TestJavaParserCanParse(t *testing.T) {
-	p := &JavaParser{}
-
-	cases := []struct {
-		filename string
-		want     bool
-	}{
-		{"Main.java", true},
-		{"UserService.java", true},
-		{"main.go", false},
-		{"app.py", false},
-		{"index.ts", false},
-	}
-
-	for _, tc := range cases {
-		got := p.CanParse(tc.filename)
-		if got != tc.want {
-			t.Errorf("CanParse(%q) = %v, want %v", tc.filename, got, tc.want)
-		}
-	}
-}
 
 func TestJavaParserParse_Imports(t *testing.T) {
-	p := &JavaParser{}
+	p := &TreeSitterParser{}
 
 	content, err := os.ReadFile("../../testdata/java-project/src/Main.java")
 	if err != nil {
@@ -60,7 +39,7 @@ func TestJavaParserParse_Imports(t *testing.T) {
 }
 
 func TestJavaParserParse_Exports(t *testing.T) {
-	p := &JavaParser{}
+	p := &TreeSitterParser{}
 
 	content, err := os.ReadFile("../../testdata/java-project/src/Main.java")
 	if err != nil {
@@ -88,7 +67,7 @@ func TestJavaParserParse_Exports(t *testing.T) {
 }
 
 func TestJavaParserParse_Entrypoint(t *testing.T) {
-	p := &JavaParser{}
+	p := &TreeSitterParser{}
 
 	content, err := os.ReadFile("../../testdata/java-project/src/Main.java")
 	if err != nil {
@@ -106,7 +85,7 @@ func TestJavaParserParse_Entrypoint(t *testing.T) {
 }
 
 func TestJavaParserParse_NoEntrypoint(t *testing.T) {
-	p := &JavaParser{}
+	p := &TreeSitterParser{}
 
 	content := []byte(`package com.example;
 

internal/parser/java_test.go

@@ -30,10 +30,7 @@ var registry []Parser
 func init() {
 	registry = []Parser{
 		&GoParser{},
-		&TypeScriptParser{},
-		&PythonParser{},
-		&RustParser{},
-		&JavaParser{},
+		&TreeSitterParser{},
 		&GenericParser{},
 	}
 }

internal/parser/parser.go

@@ -6,31 +6,9 @@ import (
 	"testing"
 )
 
-func TestPythonParserCanParse(t *testing.T) {
-	p := &PythonParser{}
-
-	cases := []struct {
-		filename string
-		want     bool
-	}{
-		{"app.py", true},
-		{"__init__.py", true},
-		{"setup.py", true},
-		{"main.go", false},
-		{"index.ts", false},
-		{"README.md", false},
-	}
-
-	for _, tc := range cases {
-		got := p.CanParse(tc.filename)
-		if got != tc.want {
-			t.Errorf("CanParse(%q) = %v, want %v", tc.filename, got, tc.want)
-		}
-	}
-}
 
 func TestPythonParserParse_Imports(t *testing.T) {
-	p := &PythonParser{}
+	p := &TreeSitterParser{}
 
 	content, err := os.ReadFile("../../testdata/python-project/app.py")
 	if err != nil {
@@ -62,7 +40,7 @@ func TestPythonParserParse_Imports(t *testing.T) {
 }
 
 func TestPythonParserParse_Exports(t *testing.T) {
-	p := &PythonParser{}
+	p := &TreeSitterParser{}
 
 	content, err := os.ReadFile("../../testdata/python-project/app.py")
 	if err != nil {
@@ -98,7 +76,7 @@ func TestPythonParserParse_Exports(t *testing.T) {
 }
 
 func TestPythonParserParse_Entrypoint(t *testing.T) {
-	p := &PythonParser{}
+	p := &TreeSitterParser{}
 
 	content, err := os.ReadFile("../../testdata/python-project/app.py")
 	if err != nil {
@@ -116,7 +94,7 @@ func TestPythonParserParse_Entrypoint(t *testing.T) {
 }
 
 func TestPythonParserParse_NoEntrypoint(t *testing.T) {
-	p := &PythonParser{}
+	p := &TreeSitterParser{}
 
 	content := []byte(`def helper():
     pass
@@ -136,7 +114,7 @@ class MyClass:
 }
 
 func TestPythonParserParse_LineCount(t *testing.T) {
-	p := &PythonParser{}
+	p := &TreeSitterParser{}
 
 	content := []byte("import os\nimport sys\n\nprint('hello')\n")
 	info, err := p.Parse("script.py", content)