feat: add OIDC/SSO authentication (#3)

Add OpenID Connect (OIDC) authentication alongside existing
username/password login. Users can log in via any standards-compliant
OIDC provider (Keycloak, Authentik, Authelia, Google, Azure AD, Okta)
while preserving full backward compatibility.

- OIDC Fastify plugin with lazy discovery, PKCE, cookie-based sessions
- Login page OIDC button, auth hook updates, settings dialog badges
- 28 integration tests, OIDC setup guide with provider examples
- Fix pre-existing test failures (content-aware-crop, watermark, SVGZ)
- WAL checkpoint fix for SQLite test stability

Closes #3

# Conflicts:
#	apps/api/src/lib/env.ts
#	apps/api/src/routes/tools/watermark-image.ts
#	pnpm-lock.yaml
#	tests/integration/color-palette.test.ts
#	tests/integration/compare.test.ts
#	tests/integration/watermark-image.test.ts

docker/Dockerfile

@@ -273,7 +273,10 @@ ENV PORT=1349 \
     SESSION_DURATION_HOURS=168 \
     LOGIN_ATTEMPT_LIMIT=500 \
     LOG_LEVEL=info \
-    TRUST_PROXY=true
+    TRUST_PROXY=true \
+    OIDC_ENABLED=false \
+    EXTERNAL_URL= \
+    COOKIE_SECRET=
 
 # NVIDIA Container Toolkit env vars (harmless on non-GPU systems)
 ENV NVIDIA_VISIBLE_DEVICES=all \

docker/docker-compose-gpu.yml

@@ -37,6 +37,20 @@ services:
       - MAX_USERS=${MAX_USERS:-0}
       - SESSION_DURATION_HOURS=${SESSION_DURATION_HOURS:-168}
       - TRUST_PROXY=${TRUST_PROXY:-true}
+      # OIDC Authentication (optional)
+      # - EXTERNAL_URL=https://photos.example.com
+      # - OIDC_ENABLED=false
+      # - OIDC_ISSUER_URL=
+      # - OIDC_CLIENT_ID=
+      # - OIDC_CLIENT_SECRET=
+      # - OIDC_SCOPES=openid profile email
+      # - OIDC_AUTO_CREATE_USERS=true
+      # - OIDC_DEFAULT_ROLE=user
+      # - OIDC_AUTO_LINK_USERS=false
+      # - OIDC_PROVIDER_NAME=
+      # - OIDC_USERNAME_CLAIM=preferred_username
+      # - OIDC_CLOCK_TOLERANCE=30
+      # - COOKIE_SECRET=
     restart: unless-stopped
     # --- Security hardening ---
     mem_limit: 8g

docker/docker-compose.yml

@@ -36,6 +36,20 @@ services:
       - MAX_USERS=${MAX_USERS:-0}
       - SESSION_DURATION_HOURS=${SESSION_DURATION_HOURS:-168}
       - TRUST_PROXY=${TRUST_PROXY:-true}
+      # OIDC Authentication (optional)
+      # - EXTERNAL_URL=https://photos.example.com
+      # - OIDC_ENABLED=false
+      # - OIDC_ISSUER_URL=
+      # - OIDC_CLIENT_ID=
+      # - OIDC_CLIENT_SECRET=
+      # - OIDC_SCOPES=openid profile email
+      # - OIDC_AUTO_CREATE_USERS=true
+      # - OIDC_DEFAULT_ROLE=user
+      # - OIDC_AUTO_LINK_USERS=false
+      # - OIDC_PROVIDER_NAME=
+      # - OIDC_USERNAME_CLAIM=preferred_username
+      # - OIDC_CLOCK_TOLERANCE=30
+      # - COOKIE_SECRET=
     restart: unless-stopped
     # --- Security hardening ---
     mem_limit: 4g