Keep desktop skills up to date automatically (#1309)

* Keep installed desktop skills up to date

* Preserve user files during skill sync

packages/desktop/src/integrations/skills/sync.ts

@@ -1,3 +1,4 @@
+import { createHash } from "node:crypto";
 import { promises as fs } from "node:fs";
 import path from "node:path";
 
@@ -15,6 +16,13 @@ export interface SkillSyncResult {
   processedSkills: number;
 }
 
+const MANAGED_FILES_MANIFEST = ".paseo-managed-files.json";
+
+interface ManagedFilesManifest {
+  version: 1;
+  files: Record<string, string>;
+}
+
 async function writeFileIfChanged(srcPath: string, dstPath: string): Promise<boolean> {
   const src = await fs.readFile(srcPath);
   const dst = await fs.readFile(dstPath).catch(() => null);
@@ -30,10 +38,12 @@ export async function listFilesRecursive(rootDir: string): Promise<string[]> {
     const entries = await fs.readdir(dir, { withFileTypes: true });
     for (const entry of entries) {
       const full = path.join(dir, entry.name);
+      const rel = path.relative(rootDir, full);
+      if (rel === MANAGED_FILES_MANIFEST) continue;
       if (entry.isDirectory()) {
         await walk(full);
       } else if (entry.isFile()) {
-        out.push(path.relative(rootDir, full));
+        out.push(rel);
       }
     }
   }
@@ -41,14 +51,89 @@ export async function listFilesRecursive(rootDir: string): Promise<string[]> {
   return out;
 }
 
+async function readManagedFilesManifest(dstDir: string): Promise<ManagedFilesManifest | null> {
+  const raw = await fs
+    .readFile(path.join(dstDir, MANAGED_FILES_MANIFEST), "utf-8")
+    .catch(() => null);
+  if (!raw) return null;
+  const parsed = safeParseJson(raw) as Partial<ManagedFilesManifest> | null;
+  if (!parsed) return null;
+  if (parsed.version !== 1 || typeof parsed.files !== "object" || parsed.files === null)
+    return null;
+  return { version: 1, files: parsed.files as Record<string, string> };
+}
+
+function safeParseJson(raw: string): unknown {
+  try {
+    return JSON.parse(raw);
+  } catch {
+    return null;
+  }
+}
+
+async function hashFile(filePath: string): Promise<string> {
+  const buf = await fs.readFile(filePath);
+  return createHash("sha256").update(buf).digest("hex");
+}
+
+async function writeManifestIfChanged(
+  dstDir: string,
+  files: Record<string, string>,
+): Promise<boolean> {
+  const manifest: ManagedFilesManifest = { version: 1, files };
+  const next = `${JSON.stringify(manifest, null, 2)}\n`;
+  const manifestPath = path.join(dstDir, MANAGED_FILES_MANIFEST);
+  const current = await fs.readFile(manifestPath, "utf-8").catch(() => null);
+  if (current === next) return false;
+  await fs.mkdir(dstDir, { recursive: true });
+  await fs.writeFile(manifestPath, next);
+  return true;
+}
+
+async function pruneEmptyParentDirs(rootDir: string, rels: readonly string[]): Promise<void> {
+  const dirs = new Set<string>();
+  for (const rel of rels) {
+    let dir = path.dirname(rel);
+    while (dir !== ".") {
+      dirs.add(dir);
+      dir = path.dirname(dir);
+    }
+  }
+  const deepestFirst = [...dirs].sort(
+    (a, b) => b.split(path.sep).length - a.split(path.sep).length,
+  );
+  for (const rel of deepestFirst) {
+    await fs.rmdir(path.join(rootDir, rel)).catch(() => {});
+  }
+}
+
 async function syncDirectoryFiles(srcDir: string, dstDir: string): Promise<number> {
   const files = await listFilesRecursive(srcDir);
+  const srcFileSet = new Set(files);
+  const srcHashes: Record<string, string> = {};
+  for (const rel of files) {
+    srcHashes[rel] = await hashFile(path.join(srcDir, rel));
+  }
+  const previousManifest = await readManagedFilesManifest(dstDir);
   let changed = 0;
   for (const rel of files) {
     if (await writeFileIfChanged(path.join(srcDir, rel), path.join(dstDir, rel))) {
       changed++;
     }
   }
+
+  const deletedRels: string[] = [];
+  for (const [rel, previousHash] of Object.entries(previousManifest?.files ?? {})) {
+    if (srcFileSet.has(rel)) continue;
+    const dstPath = path.join(dstDir, rel);
+    const currentHash = await hashFile(dstPath).catch(() => null);
+    if (currentHash !== previousHash) continue;
+    await fs.rm(dstPath, { force: true });
+    deletedRels.push(rel);
+    changed++;
+  }
+  await pruneEmptyParentDirs(dstDir, deletedRels);
+  if (await writeManifestIfChanged(dstDir, srcHashes)) changed++;
   return changed;
 }