Remove pull integration; persist push log to DB (last 50 per hotel)

- Remove TravelLine/netup-pms pull route (travelline.ts unused)
- Remove pull integration section from TvWelcomePage (token field, API URL, etc.)
- Migration 008: netup_push_log table (hotel_id, action, status, request/response body)
- recordPush() now writes to DB in addition to in-memory buffer
- getLog reads from DB so logs survive server restarts
- clearLog deletes from DB
- Limit enforced: 50 rows per hotel (oldest auto-deleted)

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

backend/migrations/008_netup_push_log.sql

@@ -0,0 +1,16 @@
+CREATE TABLE IF NOT EXISTS netup_push_log (
+  id          BIGSERIAL PRIMARY KEY,
+  hotel_id    UUID NOT NULL REFERENCES hotels(id) ON DELETE CASCADE,
+  ts          TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+  action      TEXT NOT NULL,          -- 'check-in' | 'check-out' | 'message'
+  room_number TEXT NOT NULL DEFAULT '',
+  netup_room  TEXT NOT NULL DEFAULT '',
+  url         TEXT NOT NULL DEFAULT '',
+  request_body  JSONB,
+  status      TEXT NOT NULL,          -- 'ok' | 'error' | 'skipped'
+  http_status INT,
+  response_body TEXT,
+  error       TEXT
+);
+
+CREATE INDEX IF NOT EXISTS idx_netup_push_log_hotel_ts ON netup_push_log(hotel_id, ts DESC);