feat: initialize events app with calendars, slots, tickets, and internal API

Extract events/calendar functionality into standalone microservice:
- app.py and events_api.py from apps/events/
- Calendar blueprints (calendars, calendar, calendar_entries, calendar_entry, day, slots, slot, ticket_types, ticket_type)
- Templates for all calendar/event views including admin
- Dockerfile (APP_MODULE=app:app, IMAGE=events)
- entrypoint.sh (no Alembic - migrations managed by blog app)
- Gitea CI workflow for build and deploy

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

entrypoint.sh

@@ -0,0 +1,29 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Optional: wait for Postgres to be reachable
+if [[ -n "${DATABASE_HOST:-}" && -n "${DATABASE_PORT:-}" ]]; then
+  echo "Waiting for Postgres at ${DATABASE_HOST}:${DATABASE_PORT}..."
+  for i in {1..60}; do
+    (echo > /dev/tcp/${DATABASE_HOST}/${DATABASE_PORT}) >/dev/null 2>&1 && break || true
+    sleep 1
+  done
+fi
+
+# NOTE: Events app does NOT run Alembic migrations.
+# Migrations are managed by the blog app which owns the shared database schema.
+
+# Clear Redis page cache on deploy
+if [[ -n "${REDIS_URL:-}" && "${REDIS_URL}" != "no" ]]; then
+  echo "Flushing Redis cache..."
+  python3 -c "
+import redis, os
+r = redis.from_url(os.environ['REDIS_URL'])
+r.flushall()
+print('Redis cache cleared.')
+" || echo "Redis flush failed (non-fatal), continuing..."
+fi
+
+# Start the app
+echo "Starting Hypercorn (${APP_MODULE:-app:app})..."
+PYTHONUNBUFFERED=1 exec hypercorn "${APP_MODULE:-app:app}" --bind 0.0.0.0:${PORT:-8000}