feat(tools): add ast-grep tools for AST-aware code search and transformation

- Add ast_grep_search for pattern-based code search (25 languages)
- Add ast_grep_replace for AST-aware code rewriting with dry-run
- Add ast_grep_analyze for in-memory code analysis (NAPI)
- Add ast_grep_transform for in-memory code transformation
- Add ast_grep_languages to list supported languages

src/tools/ast-grep/utils.ts

@@ -0,0 +1,72 @@
+import type { CliMatch, AnalyzeResult } from "./types"
+
+export function formatSearchResult(matches: CliMatch[]): string {
+  if (matches.length === 0) {
+    return "No matches found"
+  }
+
+  const lines: string[] = [`Found ${matches.length} match(es):\n`]
+
+  for (const match of matches) {
+    const loc = `${match.file}:${match.range.start.line + 1}:${match.range.start.column + 1}`
+    lines.push(`${loc}`)
+    lines.push(`  ${match.lines.trim()}`)
+    lines.push("")
+  }
+
+  return lines.join("\n")
+}
+
+export function formatReplaceResult(matches: CliMatch[], isDryRun: boolean): string {
+  if (matches.length === 0) {
+    return "No matches found to replace"
+  }
+
+  const prefix = isDryRun ? "[DRY RUN] " : ""
+  const lines: string[] = [`${prefix}${matches.length} replacement(s):\n`]
+
+  for (const match of matches) {
+    const loc = `${match.file}:${match.range.start.line + 1}:${match.range.start.column + 1}`
+    lines.push(`${loc}`)
+    lines.push(`  ${match.text}`)
+    lines.push("")
+  }
+
+  if (isDryRun) {
+    lines.push("Use dryRun=false to apply changes")
+  }
+
+  return lines.join("\n")
+}
+
+export function formatAnalyzeResult(results: AnalyzeResult[], extractedMetaVars: boolean): string {
+  if (results.length === 0) {
+    return "No matches found"
+  }
+
+  const lines: string[] = [`Found ${results.length} match(es):\n`]
+
+  for (const result of results) {
+    const loc = `L${result.range.start.line + 1}:${result.range.start.column + 1}`
+    lines.push(`[${loc}] (${result.kind})`)
+    lines.push(`  ${result.text}`)
+
+    if (extractedMetaVars && result.metaVariables.length > 0) {
+      lines.push("  Meta-variables:")
+      for (const mv of result.metaVariables) {
+        lines.push(`    $${mv.name} = "${mv.text}" (${mv.kind})`)
+      }
+    }
+    lines.push("")
+  }
+
+  return lines.join("\n")
+}
+
+export function formatTransformResult(original: string, transformed: string, editCount: number): string {
+  if (editCount === 0) {
+    return "No matches found to transform"
+  }
+
+  return `Transformed (${editCount} edit(s)):\n\`\`\`\n${transformed}\n\`\`\``
+}