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>

tests/test_api.py

@@ -1,5 +1,4 @@
 import importlib
-import shutil
 from pathlib import Path
 
 import pytest
@@ -10,33 +9,24 @@ def test_root_serves_html(client):
     response = client.get("/")
     assert response.status_code == 200
     assert "text/html" in response.headers["content-type"]
-    assert "Python Editor" in response.text
+    assert "LED Editor" in response.text
 
 
 def test_editor_route_serves_editor_html(client):
     response = client.get("/editor")
     assert response.status_code == 200
     assert "text/html" in response.headers["content-type"]
-    assert "Python Editor" in response.text
+    assert "LED Editor" in response.text
 
 
-def test_workspace_lib_seeded_from_bundle_on_startup(client, tmp_path):
-    """Populate WORKSPACE_ROOT/lib with shipped stubs when absent (empty volume / fresh tmp)."""
-    lib_dir = tmp_path / "lib"
-    assert (lib_dir / "machine.py").is_file()
-    assert (lib_dir / "neopixel.py").is_file()
-    assert len((lib_dir / "machine.py").read_text(encoding="utf-8")) > 0
-
-
-def test_workspace_lib_repops_when_removed_after_startup(client, tmp_path):
-    """Touching lib via the API restores bundled stubs after the workspace lib dir is wiped."""
-    lib_dir = tmp_path / "lib"
-    assert (lib_dir / "machine.py").is_file()
-    shutil.rmtree(lib_dir)
-
+def test_lib_served_directly_from_repo_bundle(client, tmp_path):
+    """`lib/` reads come straight from repo `lib/`; no workspace cache is created."""
     resp = client.get("/api/file/lib/machine.py")
     assert resp.status_code == 200
-    assert (lib_dir / "machine.py").is_file()
+    body = resp.json().get("content", "")
+    assert "class Pin" in body and len(body) > 0
+    assert not (tmp_path / "lib").exists()
+
 
 def test_list_files_hides_dotfiles_and_reports_sizes(client, tmp_path):
     (tmp_path / ".hidden.txt").write_text("secret", encoding="utf-8")
@@ -76,9 +66,6 @@ def test_save_file_collapses_duplicate_scoped_prefix(client, tmp_path):
 
 
 def test_lib_folder_is_read_only_for_mutations(client, tmp_path):
-    lib_dir = tmp_path / "lib"
-    lib_dir.mkdir(exist_ok=True)
-    (lib_dir / "helper.py").write_text("x = 1\n", encoding="utf-8")
     code_dir = tmp_path / "code"
     code_dir.mkdir()
     (code_dir / "main.py").write_text("print('ok')\n", encoding="utf-8")
@@ -86,7 +73,7 @@ def test_lib_folder_is_read_only_for_mutations(client, tmp_path):
     save_blocked = client.post("/api/file/lib/new.txt", json={"content": "nope"})
     assert save_blocked.status_code == 403
 
-    delete_blocked = client.delete("/api/file/lib/helper.py")
+    delete_blocked = client.delete("/api/file/lib/machine.py")
     assert delete_blocked.status_code == 403
 
     move_blocked = client.post(
@@ -252,14 +239,14 @@ def test_folder_delete_errors(client, tmp_path):
 def test_workspace_py_sources_returns_python_files(client, tmp_path):
     (tmp_path / "code").mkdir()
     (tmp_path / "code" / "app.py").write_text("x = 1\n", encoding="utf-8")
-    (tmp_path / "lib").mkdir(exist_ok=True)
-    (tmp_path / "lib" / "util.py").write_text("def f():\n    pass\n", encoding="utf-8")
 
     response = client.get("/api/workspace/py-sources")
     assert response.status_code == 200
     files = response.json()["files"]
     assert files["code/app.py"] == "x = 1\n"
-    assert "lib/util.py" in files
+    # Bundled stubs from repo `lib/` are merged in automatically.
+    assert "lib/machine.py" in files
+    assert "lib/neopixel.py" in files
 
 
 def test_api_requires_bearer_when_editor_api_key_set(tmp_path, monkeypatch):
@@ -284,7 +271,9 @@ def test_api_requires_bearer_when_editor_api_key_set(tmp_path, monkeypatch):
         assert ok.status_code == 200
 
 
-def test_create_app_startup_creates_lib(tmp_path, monkeypatch):
+def test_create_app_startup_does_not_seed_workspace_lib(tmp_path, monkeypatch):
+    """Bundle stubs are read directly from repo `lib/`, so startup must not create
+    a `WORKSPACE_ROOT/lib` cache."""
     import editor_app.config as config
     import editor_app.db.session as db_sess
     import editor_app.main as main
@@ -302,4 +291,4 @@ def test_create_app_startup_creates_lib(tmp_path, monkeypatch):
     assert not (tmp_path / "lib").exists()
     with TestClient(main.app) as _client:
         _client.get("/api/auth/status")
-    assert (tmp_path / "lib").is_dir()
+    assert not (tmp_path / "lib").exists()