* feat(security): encrypt server-owned credentials at rest Introduce AES-256-GCM at-rest encryption (HKDF-derived from a required SECRET_KEY) for server-owned credentials, with row-bound AAD, a versioned enc:v1: envelope, and an idempotent startup backfill. - internal/secret: cipher + RowAAD/SettingsAAD + the startup backfill engine. - SECRET_KEY required at bootstrap; cipher threaded as an explicit dependency. - server_settings: EncryptedSettingsRepo decorator over the audited SensitiveSettingKeys (also drives admin redaction); the config watcher and watch-sync settings reads decrypt too. - Arr keys inline-encrypted; the ambiguous SecretResolver indirection removed from requests/autoscan. - Per-table columns encrypted: subtitles, watch-sync, webhook-sync (not webhook_secret), history-import, and the jellycompat session's bridged Silo access/refresh tokens. - Startup backfill (resolve-then-encrypt for arr refs) is best-effort and primary-node gated. Equality-looked-up secrets and plugin_runtime_configs.config_value are out of scope (need hashing / cross-repo design) — see docs/architecture/secret-encryption.md. Refs #45 Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com> * chore(compose): require SECRET_KEY in docker-compose The server now fatals without SECRET_KEY, so the integrated service (and the commented distributed proxy/transcode examples) pass it through with a fail-fast guard matching the existing MEDIA_ROOT pattern. Distributed worker nodes must use the SAME key as the primary to decrypt shared data. Generate with: openssl rand -base64 48. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com> * fix(security): encrypt history import session credentials --------- Co-authored-by: Claude Opus 4.8 (1M context) <noreply@anthropic.com>