Add local-mode workspace, ZIP import/export, and richer pin/ADC/serial sims

Boot:
- Editor now picks local vs server mode based on URL flag, sign-in
  state, and a stale local-mode flag. Signed-in users are no longer
  bounced to IndexedDB if they had previously clicked "Use locally".

Local mode:
- New LocalWorkspaceClient (src/static/local-workspace.js) with
  pluggable IndexedDB and File System Access backends. Picked folder
  handles persist across reloads with a Reconnect button when the
  permission lapses.
- Static-only host: scripts/serve_static_editor.py serves src/static/
  with COOP/COEP so SharedArrayBuffer-backed sims keep working.
- Bundled MicroPython stubs ship under src/static/bundled-lib/ for
  static hosting; FastAPI also exposes them at /api/public/lib-bundle.

Workspace import / export:
- Zero-dep ZIP encoder + reader (STORE + DEFLATE via
  DecompressionStream). Export/Import buttons in the workspace badge
  work in both local and server modes; imports are confined to code/.

Pin / ADC / Serial simulation:
- machine.py grows ADC, UART, expanded Pin, and PWM mocks, all driven
  by SharedArrayBuffer when cross-origin isolated and falling back to
  postMessage + [pin-out] stdout markers otherwise — pins, ADC slider,
  and serial input now keep working over plain HTTP / LAN-IP origins.
- NeoPixel pins are claimed via a [pin-claim] marker and dropped from
  the Pins panel so the data line doesn't flicker per write().
- New demos: adc_slider_demo.py, pin_demo.py, serial_demo.py.

Lib layout:
- Single source of truth at repo lib/; workspace/lib/ caching layer
  removed and the directory deleted. Filesystem service reads stubs
  directly from PROJECT_ROOT/lib.

UI:
- Home page slimmed to "Sign in" + "Use locally" with optional editor
  / manage-users links. Admin user/invite UI moved to /users.
- Workspace badge gains storage indicator, Folder…/Reconnect, Export,
  Import, and Exit controls.
- Mobile-friendly tweaks: safer-area padding, larger touch targets,
  iOS-zoom-proof serial input, file-tree highlight fix.

Tests:
- test_auth.py patches PROJECT_ROOT for the lib-shared test so the
  repo-root lib refactor stays green. test_api.py asserts the new
  "LED Editor" branding.

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

src/editor_app/services/filesystem.py

@@ -15,12 +15,13 @@ def _workspace_root(workspace_root: Path | None = None) -> Path:
 
 
 def _shared_lib_root() -> Path:
-    """Shared MicroPython stubs live under WORKSPACE_ROOT/lib; seed from bundle if missing (e.g. volume wiped)."""
-    lib = (config.WORKSPACE_ROOT.resolve() / LIB_DIR_NAME).resolve()
-    from editor_app.services.user_workspace import ensure_workspace_lib
+    """Shared MicroPython stubs ship in the repo `lib/` directory and are read directly.
 
-    ensure_workspace_lib()
-    return lib
+    Treating the bundle as the single source of truth means there is no on-disk
+    `workspace/lib/` cache to keep in sync — updates to e.g. `machine.py` flow
+    straight through to Pyodide and the file tree.
+    """
+    return (config.PROJECT_ROOT / LIB_DIR_NAME).resolve()
 
 
 def normalize_relative_path(relative_path: str) -> str:
@@ -55,16 +56,8 @@ def resolve_workspace_path(relative_path: str, workspace_root: Path | None = Non
 
 
 def _is_path_in_lib(target_path: Path, workspace_root: Path | None = None) -> bool:
-    workspace = _workspace_root(workspace_root)
-    lib_root = (workspace / LIB_DIR_NAME).resolve()
-    shared_lib_root = _shared_lib_root()
     try:
-        target_path.resolve().relative_to(lib_root)
-        return True
-    except ValueError:
-        pass
-    try:
-        target_path.resolve().relative_to(shared_lib_root)
+        target_path.resolve().relative_to(_shared_lib_root())
         return True
     except ValueError:
         return False