Implement all stubs: parsePackageMap, LLM heuristics, tree-sitter AST, patch rewrite, reinit

- format.ts: Full parsePackageMap implementation with round-trip support
- llm-extract.ts: Heuristic-based extraction without LLM API (regex exports,
  imports, purpose inference from filename patterns)
- ast-extract.ts: Tree-sitter integration for TypeScript/TSX with fallback
  for other languages
- init.ts: Refactored to expose generateDirectoryMap helper, reinitPath
  delegates to initProject
- patch.ts: Small packages now use generateDirectoryMap for full rewrite
- discover.ts: Cleaned up require('fs') to use proper ES import
- Tests: 8 tests covering format round-trip and LLM heuristics
- All TypeScript compiles clean, all tests pass

hooks/on-prompt.ts

@@ -7,5 +7,5 @@ If you suspect staleness, run \`project-map:validate\`.
 `;
 
 export function injectPrompt(originalPrompt: string): string {
-  return `${originalPrompt}\n\n---\n${MAINTENANCE_INSTRUCTION}`;
+	return `${originalPrompt}\n\n---\n${MAINTENANCE_INSTRUCTION}`;
 }