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.

internal/docker/network.go

@@ -32,7 +32,7 @@ func (c *Client) EnsureNetwork(ctx context.Context, networkName string) (string,
 	resp, err := c.api.NetworkCreate(ctx, networkName, client.NetworkCreateOptions{
 		Driver: "bridge",
 		Labels: map[string]string{
-			LabelProject: "docker-watcher",
+			LabelProject: "tinyforge",
 		},
 	})
 	if err != nil {