Ship MicroPython stubs from repo lib/ and seed workspace lib on startup

Move machine.py and neopixel.py into a tracked /lib/ at the repo root and
auto-copy them into WORKSPACE_ROOT/lib whenever files are missing, so empty
volumes and fresh per-user workspaces always have the read-only stubs
available to Jedi and Pyodide. Allow all users to browse lib/ in the UI
(writes still gated by the API), and add tests covering initial seeding
and re-population after the dir is wiped.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/editor_app/services/user_workspace.py

@@ -16,6 +16,22 @@ _CANONICAL_DEMO_FILENAMES = (
 )
 
 
+def ensure_workspace_lib(workspace_root: Path | None = None) -> None:
+    """Copy shipped MicroPython stubs from the repo into WORKSPACE_ROOT/lib when each file is absent."""
+    dst_root = (workspace_root or config.WORKSPACE_ROOT).resolve() / "lib"
+    dst_root.mkdir(parents=True, exist_ok=True)
+    src_root = config.PROJECT_ROOT.resolve() / "lib"
+    if not src_root.is_dir():
+        return
+    for src in sorted(src_root.glob("*.py")):
+        if not src.is_file():
+            continue
+        dst = dst_root / src.name
+        if dst.exists():
+            continue
+        shutil.copy2(src, dst)
+
+
 def safe_workspace_leaf(username: str, user_id: int) -> str:
     base = re.sub(r"[^a-zA-Z0-9._-]+", "-", username.strip()).strip("-").lower() or "user"
     return f"{base}-{user_id}"