Implement tasks 60, 61, 62: backups, rate limiting, structured logging

Task 60 — Postgres backups:
- deploy/backups/: backup.sh (pg_dump -Fc nightly), retain.sh (14/8/6 tiers),
  restore.sh, entrypoint.sh, crontab
- famapp-backup Alpine service + backups volume added to deploy/compose.yaml
- Restore procedure in deploy/backups/README.md

Task 61 — Rate limiting on share links:
- src/lib/rate-limit.ts: Edge-compatible sliding-window counter (50/min, LRU eviction)
  with consume(), isRateLimited(), recordFailure() exports
- middleware.ts: enforces 429 with Retry-After: 60 for /s/[token] (IP + token prefix)
- /s/[token]/page.tsx: tracks only failed resolveShareToken calls via recordFailure()

Task 62 — Structured logging:
- pino + pino-pretty installed; serverExternalPackages added to next.config.ts
- src/lib/logger.ts: JSON in production, pretty in dev, level from LOG_LEVEL env
- middleware.ts: structured JSON request log (method, path, status, ms, authenticated)
- _core/push.ts, notify.ts, reminders.ts: console.error/log → logger.error/info

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

deploy/backups/restore.sh

@@ -0,0 +1,26 @@
+#!/bin/sh
+# Restore a pg_dump (-Fc format) to a target Postgres database.
+# The target DB must already exist and be empty (or you accept overwriting data).
+#
+# Usage:
+#   restore.sh <dump-file> <target-db-url>
+#
+# Example (inside the backup container):
+#   /scripts/restore.sh \
+#     /backups/famapp/daily/2024-06-01.dump \
+#     postgres://famapp:secret@famapp-db:5432/famapp
+#
+# Example (from the host via docker exec):
+#   docker exec famapp-backup-1 /scripts/restore.sh \
+#     /backups/famapp/daily/2024-06-01.dump \
+#     postgres://famapp:secret@famapp-db:5432/famapp_restore
+set -eu
+
+DUMP_FILE="${1:?Usage: restore.sh <dump-file> <target-db-url>}"
+TARGET_URL="${2:?Usage: restore.sh <dump-file> <target-db-url>}"
+
+[ -f "$DUMP_FILE" ] || { echo "[restore] ERROR: $DUMP_FILE not found"; exit 1; }
+
+echo "[restore] $DUMP_FILE → $TARGET_URL"
+pg_restore -d "$TARGET_URL" --no-owner --no-acl --exit-on-error "$DUMP_FILE"
+echo "[restore] done"