Store a SHA-256 hash of the webhook secret in a new webhook_secret_hash
column. FindAppByWebhookSecret now hashes the incoming secret and queries
by hash, eliminating the SQL string comparison timing side-channel.
- Add migration 005_add_webhook_secret_hash.sql
- Add database.HashWebhookSecret() helper
- Backfill existing secrets on startup
- Update App model to include WebhookSecretHash in all queries
- Update app creation to compute hash at insert time
- Add TestHashWebhookSecret unit test
- Update all test fixtures to set WebhookSecretHash
Closes#13
- Replace UUID with ULID for app ID generation (lexicographically sortable)
- Remove container_id column from apps table (migration 002)
- Add upaas.id Docker label to identify containers by app ID
- Implement FindContainerByAppID in Docker client to query by label
- Update handlers and deploy service to use label-based container lookup
- Show system-managed upaas.id label in UI with editing disabled
Container association is now determined dynamically via Docker label
rather than stored in the database, making the system more resilient
to container recreation or external changes.