Widget system Phase 4b: per-widget gear-icon config dialogs

Replaces the Photos/Calendar/Whiteboard tabs with a single Layout page
(now the frame's landing route) where each widget gets a gear icon
opening a dialog scoped to that specific widget's own settings. This
was the missing piece for genuinely independent same-type widgets --
"the Calendar tab" never made sense once a frame could hold more than
one calendar widget with different settings.

Data layer: FrameCalendar re-keyed from frame_id to widget_id, so each
calendar widget has its own independent included-calendars set. The
rekey runs as an unconditional post-startup step (like the existing
widget backfill), not a numbered migration -- it depends on calendar
widgets already existing, which themselves come from that same
backfill step, not from schema migration. Registering it as a numbered
migration would have run it first during a real upgrade, silently
dropping every row; caught by a new test that exercises the raw-SQL
upgrade path instead of the fresh-install create_all() shortcut every
other migration test takes.

API layer: every endpoint that used to assume "the frame's widget of
this type" (photo queue/thumbnail/preview, calendar select/color/
tasks/weather, whiteboard source/browse/preview) moved into
api_widgets.py under /api/frames/{id}/widgets/{widget_id}/..., with a
new require_widget_view/control dependency pair mirroring the existing
frame-level ones. Device status (battery/last-seen/firmware) got its
own frame-level /status endpoint, split out of the old photo-specific
/queue it used to piggyback on -- fixes the status bar going silently
blank on any frame without a photo widget.

UI layer: each widget type's existing settings markup/JS was ported
into a dialog partial + an explicit init/close function pair (the
content is now fetched and injected on demand, not loaded at page load
time). window.FRAME_API is repointed to the open dialog's widget-scoped
API base for its duration and restored on close; a separate
window.FRAME_BASE_API stays stable for the always-present header/
status-bar scripts.

Caught during manual browser testing: the consolidated config-save
endpoint initially expected a JSON body while the copied-over dialog JS
posts form-urlencoded data (the old convention) -- fixed to match, with
new HTTP-level test coverage that would have caught it immediately.

server/tests/test_migrations.py

@@ -17,12 +17,15 @@ from app.models import (
     CalendarWidgetConfig,
     Frame,
     FrameButtonAction,
+    FrameCalendar,
     PhotoWidgetConfig,
     ServerSettings,
     Widget,
     WhiteboardWidgetConfig,
 )
 
+from .conftest import make_user
+
 
 def test_migrations_list_is_sequential_and_unique():
     versions = [v for v, _ in MIGRATIONS]
@@ -170,11 +173,29 @@ def test_migration_16_raw_sql_path_applies_to_an_existing_pre_widget_database(db
     """Exercises _migration_16's actual CREATE TABLE statements (the real
     "existing production database upgrading past this migration"
     scenario) rather than the fresh-install create_all() shortcut, which
-    every other test in this file goes through instead."""
+    every other test in this file goes through instead. frame_calendars
+    also gets rebuilt back to its pre-rekey (frame_id-keyed) shape,
+    matching what _migration_9/_migration_11 originally produced, so
+    _ensure_frame_calendars_rekeyed has a real frame_id-shaped table to
+    migrate."""
     with db_module.engine.begin() as conn:
         for table in ("frame_button_actions", "whiteboard_widget_configs",
                       "calendar_widget_configs", "photo_widget_configs", "widgets"):
             conn.execute(text(f"DROP TABLE {table}"))
+        conn.execute(text("DROP TABLE frame_calendars"))
+        conn.execute(text(
+            "CREATE TABLE frame_calendars ("
+            "id INTEGER PRIMARY KEY, "
+            "frame_id INTEGER NOT NULL REFERENCES frames(id) ON DELETE CASCADE, "
+            "user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE, "
+            "calendar_key TEXT NOT NULL, "
+            "calendar_label TEXT NOT NULL DEFAULT '', "
+            "included INTEGER NOT NULL DEFAULT 1, "
+            "color_index INTEGER)"
+        ))
+        conn.execute(text(
+            "CREATE UNIQUE INDEX ix_frame_calendars_unique ON frame_calendars (frame_id, user_id, calendar_key)"
+        ))
         conn.execute(text("UPDATE schema_version SET version = 15"))
 
     frame = Frame(
@@ -183,8 +204,20 @@ def test_migration_16_raw_sql_path_applies_to_an_existing_pre_widget_database(db
         queue=["legacy-asset", "next-asset"], created_at=time.time(),
     )
     db_session.add(frame)
+    db_session.flush()
+    user = make_user(db_session, "legacy-owner")
     db_session.commit()
-    frame_id = frame.id
+    frame_id, user_id = frame.id, user.id
+
+    # An orphaned frame_calendars row (this frame's mode was never
+    # "calendar", so it has no calendar widget for _ensure_frame_
+    # calendars_rekeyed to attach it to) -- exercises that it's dropped
+    # cleanly rather than raising.
+    with db_module.engine.begin() as conn:
+        conn.execute(text(
+            "INSERT INTO frame_calendars (frame_id, user_id, calendar_key, calendar_label, included) "
+            "VALUES (:frame_id, :user_id, 'ics', 'Legacy Cal', 1)"
+        ), {"frame_id": frame_id, "user_id": user_id})
 
     run_migrations()
 
@@ -198,3 +231,61 @@ def test_migration_16_raw_sql_path_applies_to_an_existing_pre_widget_database(db
     assert config.album_id == "legacy-album"
     assert config.current_asset_id == "legacy-asset"
     assert config.queue == ["legacy-asset", "next-asset"]
+
+
+def test_frame_calendars_rekey_attaches_existing_rows_to_their_calendar_widget(db_session):
+    """A frame whose mode was "calendar" (not "photos") gets a calendar
+    widget from _ensure_widgets_backfilled -- _ensure_frame_calendars_
+    rekeyed should then attach the pre-existing frame_id-keyed
+    FrameCalendar row inserted below to that widget's id, not drop it.
+    This is the regression case for the ordering bug the two migration
+    tests above's setup was designed to catch: the rekey must run AFTER
+    the widget backfill, not as a numbered migration racing ahead of
+    it (see _ensure_frame_calendars_rekeyed's own docstring)."""
+    with db_module.engine.begin() as conn:
+        for table in ("frame_button_actions", "whiteboard_widget_configs",
+                      "calendar_widget_configs", "photo_widget_configs", "widgets"):
+            conn.execute(text(f"DROP TABLE {table}"))
+        conn.execute(text("DROP TABLE frame_calendars"))
+        conn.execute(text(
+            "CREATE TABLE frame_calendars ("
+            "id INTEGER PRIMARY KEY, "
+            "frame_id INTEGER NOT NULL REFERENCES frames(id) ON DELETE CASCADE, "
+            "user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE, "
+            "calendar_key TEXT NOT NULL, "
+            "calendar_label TEXT NOT NULL DEFAULT '', "
+            "included INTEGER NOT NULL DEFAULT 1, "
+            "color_index INTEGER)"
+        ))
+        conn.execute(text(
+            "CREATE UNIQUE INDEX ix_frame_calendars_unique ON frame_calendars (frame_id, user_id, calendar_key)"
+        ))
+        conn.execute(text("UPDATE schema_version SET version = 15"))
+
+    frame = Frame(
+        name="Calendar Frame", device_token="tok-cal", manage_token="mtok-cal",
+        mode="calendar", created_at=time.time(),
+    )
+    db_session.add(frame)
+    db_session.flush()
+    user = make_user(db_session, "cal-owner")
+    db_session.commit()
+    frame_id, user_id = frame.id, user.id
+
+    with db_module.engine.begin() as conn:
+        conn.execute(text(
+            "INSERT INTO frame_calendars (frame_id, user_id, calendar_key, calendar_label, included, color_index) "
+            "VALUES (:frame_id, :user_id, 'ics', 'Legacy Cal', 1, 3)"
+        ), {"frame_id": frame_id, "user_id": user_id})
+
+    run_migrations()
+
+    widget = db_session.scalars(
+        select(Widget).where(Widget.frame_id == frame_id, Widget.widget_type == "calendar")
+    ).one()
+    row = db_session.scalars(select(FrameCalendar).where(FrameCalendar.widget_id == widget.id)).one()
+    assert row.user_id == user_id
+    assert row.calendar_key == "ics"
+    assert row.calendar_label == "Legacy Cal"
+    assert row.included is True
+    assert row.color_index == 3