Initial commit: pi-project-map skill scaffolding

- Design doc with full spec (dense markdown format, hybrid AST+LLM pipeline,
  consumption model, stale data mitigation)
- Implementation plan with 6 milestones and rollout strategy
- TypeScript package structure with all source stubs
- CLI entry point, formatter, discover, init, patch, validate, extract, merge
- Pi SKILL.md with tool definitions and format documentation

src/init.ts

@@ -0,0 +1,42 @@
+import { discoverProject } from './discover.js';
+import { renderPackageMap, type PackageMapData } from './format.js';
+import { extractFileLLM } from './llm-extract.js';
+import { extractFileAST } from './ast-extract.js';
+import { mergeFileData } from './merge.js';
+import { extractPackageLLM } from './llm-extract.js';
+import { writeFileSync } from 'fs';
+import { join } from 'path';
+
+export async function initProject(rootPath: string): Promise<void> {
+  const entries = discoverProject(rootPath);
+
+  for (const entry of entries) {
+    const fileData = [];
+    for (const file of entry.files) {
+      const filePath = join(entry.dirPath, file);
+      const llmData = await extractFileLLM(filePath);
+      const astData = await extractFileAST(filePath);
+      fileData.push(mergeFileData(file, llmData, astData));
+    }
+
+    const packageData = await extractPackageLLM(entry.relativePath, fileData);
+
+    const mapData: PackageMapData = {
+      path: entry.relativePath,
+      role: packageData.role,
+      files: fileData,
+      arch: packageData.arch,
+      dirty: '-'
+    };
+
+    const outPath = join(entry.dirPath, '.pi-map.md');
+    writeFileSync(outPath, renderPackageMap(mapData));
+  }
+
+  console.log(`Generated ${entries.length} .pi-map.md files`);
+}
+
+export async function reinitPath(path: string): Promise<void> {
+  // TODO: clear dirty markers and force regeneration
+  await initProject(path);
+}