feat: add Nostr event tracking columns to events table

Migration m009 adds nostr_event_id and nostr_event_created_at to
track published NIP-52 calendar events. Enables correlation between
LNbits events and their Nostr representations.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

migrations.py

@@ -202,3 +202,15 @@ async def m008_add_event_status(db):
     await db.execute(
         "ALTER TABLE events.events ADD COLUMN status TEXT NOT NULL DEFAULT 'approved';"
     )
+
+
+async def m009_add_nostr_columns(db):
+    """
+    Add columns to track published NIP-52 Nostr calendar events.
+    """
+    await db.execute(
+        "ALTER TABLE events.events ADD COLUMN nostr_event_id TEXT;"
+    )
+    await db.execute(
+        "ALTER TABLE events.events ADD COLUMN nostr_event_created_at INTEGER;"
+    )

models.py

@@ -80,6 +80,8 @@ class Event(BaseModel):
     banner: str | None = None
     extra: EventExtra = Field(default_factory=EventExtra)
     status: str = "approved"  # proposed, approved, rejected
+    nostr_event_id: str | None = None
+    nostr_event_created_at: int | None = None
 
 
 class TicketExtra(BaseModel):