feat: add event approval workflow with admin UI

Non-admin event submissions now land in a "proposed" queue that LNbits
admins review before the event becomes ticketable and publicly listed.

- m008 adds events.events.status (proposed/approved/rejected); m010 seeds
  an events.settings singleton row with the auto_approve toggle.
- Models: Event/CreateEvent.status, EventsSettings, optional date fields
  with sensible defaults (closing_date defaults to event_end_date which
  defaults to event_start_date), PublicEvent.status surfaces the workflow
  state on the public endpoint.
- crud: get_all/public/pending_events for the admin views; get/update_settings
  for the auto_approve toggle; create_event auto-fills missing date defaults.
- views_api:
  * POST /api/v1/events accepts wallet invoice keys so anyone can submit;
    handler stamps status="proposed" for non-admins when auto_approve is off
  * /public, /all, /pending, /settings (GET+PUT), /{id}/{approve,reject},
    /{id}/tickets endpoints; literal-prefix routes declared before /{event_id}
    so FastAPI matches them correctly
  * Public GET /{event_id} bypasses sold-out / closing-window gates for
    proposed/rejected events and returns the trimmed PublicEvent so the SFC
    can render a "pending approval" banner
  * POST /tickets/{event_id} rejects when event.status != "approved"
- Frontend: index.vue gains an admin Settings card, Pending Approvals list,
  status badge column and approve/reject row actions, plus an All Users'
  Events admin table; index.js gains the data + methods + an isAdmin probe
  via GET /events/all; display.vue shows pending/rejected banners and
  hides the Buy Ticket form unless status === "approved".

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

migrations.py

@@ -200,3 +200,35 @@ async def m007_add_user_id_support(db):
     await _alter_add_column_safe(
         db, "ALTER TABLE events.ticket ADD COLUMN user_id TEXT"
     )
+
+
+async def m008_add_event_status(db):
+    """
+    Add status column to events table for the proposal/approval workflow.
+    Values: 'proposed', 'approved', 'rejected'. Existing rows default to
+    'approved' so they stay visible after upgrade.
+    """
+    await _alter_add_column_safe(
+        db,
+        "ALTER TABLE events.events ADD COLUMN status TEXT NOT NULL DEFAULT 'approved'",
+    )
+
+
+async def m010_add_events_settings(db):
+    """
+    Create the extension settings singleton row used by the admin UI to
+    toggle e.g. auto_approve.
+    """
+    await db.execute(
+        """
+        CREATE TABLE IF NOT EXISTS events.settings (
+            id INTEGER PRIMARY KEY DEFAULT 1,
+            auto_approve BOOLEAN NOT NULL DEFAULT FALSE
+        )
+        """
+    )
+    await db.execute(
+        "INSERT INTO events.settings (id, auto_approve) "
+        "SELECT 1, FALSE WHERE NOT EXISTS "
+        "(SELECT 1 FROM events.settings WHERE id = 1)"
+    )