feat(docker-watcher): phase 12 - hardening

Blue-green zero-downtime deploys, promote flow validation.
Dual auth: local (bcrypt + JWT) and OAuth2/OIDC (any provider).
Auth middleware, login page, auth settings UI.
Structured logging (slog JSON), config export to YAML.
Graceful shutdown with deploy draining.
Multi-stage Dockerfile and production docker-compose.yml.
Swap phase order: Volumes & Env before UI Polish.

go.mod

@@ -3,11 +3,15 @@ module github.com/alexei/docker-watcher
 go 1.23
 
 require (
+	github.com/coreos/go-oidc/v3 v3.11.0
 	github.com/docker/docker v27.5.1+incompatible
 	github.com/docker/go-connections v0.5.0
 	github.com/go-chi/chi/v5 v5.2.1
+	github.com/golang-jwt/jwt/v5 v5.2.1
 	github.com/google/uuid v1.6.0
 	github.com/robfig/cron/v3 v3.0.1
+	golang.org/x/crypto v0.31.0
+	golang.org/x/oauth2 v0.25.0
 	gopkg.in/yaml.v3 v3.0.1
 	modernc.org/sqlite v1.34.5
 )