feat: rename Docker Watcher to Tinyforge

Rebrand the project as Tinyforge to reflect its evolution from a Docker
container watcher into a self-hosted mini CI/deployment platform.

Rename covers: Go module path, Docker labels, DB/config filenames,
JWT issuer, Dockerfile binary, docker-compose, CI workflows, frontend
i18n, README with static sites docs, and all code comments.

docker-compose.yml

@@ -1,8 +1,8 @@
 services:
-  docker-watcher:
+  tinyforge:
     build: .
-    image: docker-watcher:latest
-    container_name: docker-watcher
+    image: tinyforge:latest
+    container_name: tinyforge
     restart: unless-stopped
     ports:
       - "8080:8080"
@@ -10,16 +10,16 @@ services:
       # Mount Docker socket for container management.
       - /var/run/docker.sock:/var/run/docker.sock
       # Persistent data (SQLite database).
-      - docker-watcher-data:/app/data
+      - tinyforge-data:/app/data
       # Optional seed config (read on first launch only).
-      - ./docker-watcher.yaml:/app/docker-watcher.yaml:ro
+      - ./tinyforge.yaml:/app/tinyforge.yaml:ro
     environment:
       # Required: protects all credentials stored in the database.
       - ENCRYPTION_KEY=${ENCRYPTION_KEY:?Set ENCRYPTION_KEY in .env}
       # Required on first launch: password for the default admin user.
       - ADMIN_PASSWORD=${ADMIN_PASSWORD:?Set ADMIN_PASSWORD in .env}
       # Optional: override seed file location.
-      - SEED_FILE=/app/docker-watcher.yaml
+      - SEED_FILE=/app/tinyforge.yaml
       # Optional: override data directory.
       - DATA_DIR=/app/data
       # Optional: override listen address.
@@ -38,7 +38,7 @@ services:
       start_period: 10s
 
 volumes:
-  docker-watcher-data:
+  tinyforge-data:
     driver: local
 
 # NOTE: The staging-net network must exist before starting.