move pi-mono into companion-cloud as apps/companion-os

- Copy all pi-mono source into apps/companion-os/
- Update Dockerfile to COPY pre-built binary instead of downloading from GitHub Releases
- Update deploy-staging.yml to build pi from source (bun compile) before Docker build
- Add apps/companion-os/** to path triggers
- No more cross-repo dispatch needed

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

packages/pi-teams/src/utils/lock.ts

@@ -0,0 +1,50 @@
+// Project: pi-teams
+import fs from "node:fs";
+
+const STALE_LOCK_TIMEOUT = 30000; // 30 seconds for a lock to be considered stale
+
+export async function withLock<T>(
+  lockPath: string,
+  fn: () => Promise<T>,
+  retries: number = 50,
+): Promise<T> {
+  const lockFile = `${lockPath}.lock`;
+
+  while (retries > 0) {
+    try {
+      // Check if lock exists and is stale
+      if (fs.existsSync(lockFile)) {
+        const stats = fs.statSync(lockFile);
+        const age = Date.now() - stats.mtimeMs;
+        if (age > STALE_LOCK_TIMEOUT) {
+          // Attempt to remove stale lock
+          try {
+            fs.unlinkSync(lockFile);
+          } catch (_error) {
+            // ignore, another process might have already removed it
+          }
+        }
+      }
+
+      fs.writeFileSync(lockFile, process.pid.toString(), { flag: "wx" });
+      break;
+    } catch (_error) {
+      retries--;
+      await new Promise((resolve) => setTimeout(resolve, 100));
+    }
+  }
+
+  if (retries === 0) {
+    throw new Error("Could not acquire lock");
+  }
+
+  try {
+    return await fn();
+  } finally {
+    try {
+      fs.unlinkSync(lockFile);
+    } catch (_error) {
+      // ignore
+    }
+  }
+}