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/format.ts

@@ -0,0 +1,40 @@
+export interface PackageMapData {
+  path: string;
+  role: string;
+  files: FileEntry[];
+  arch: string;
+  dirty?: string;
+}
+
+export interface FileEntry {
+  name: string;
+  purpose: string;
+  exports: string[];
+  deps: string[];
+}
+
+export function renderPackageMap(data: PackageMapData): string {
+  const lines: string[] = [];
+  lines.push(`# ${data.path}`);
+  lines.push(`## role`);
+  lines.push(data.role);
+  lines.push(`## files`);
+  for (const file of data.files) {
+    const exp = file.exports.length > 0 ? `exp: ${file.exports.join(', ')}` : '';
+    const dep = file.deps.length > 0 ? `dep: ${file.deps.join(', ')}` : '';
+    const parts = [`- ${file.name} | ${file.purpose}`];
+    if (exp) parts.push(exp);
+    if (dep) parts.push(dep);
+    lines.push(parts.join(' | '));
+  }
+  lines.push(`## arch`);
+  lines.push(data.arch);
+  lines.push(`## dirty`);
+  lines.push(data.dirty || '-');
+  return `${lines.join('\n')}\n`;
+}
+
+export function parsePackageMap(_markdown: string): PackageMapData {
+  // TODO: implement robust parser
+  throw new Error('parsePackageMap not yet implemented');
+}