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/api/config_export.go

@@ -4,7 +4,7 @@ import (
 	"log/slog"
 	"net/http"
 
-	"github.com/alexei/docker-watcher/internal/config"
+	"github.com/alexei/tinyforge/internal/config"
 )
 
 // exportConfig handles GET /api/config/export — downloads current state as YAML.
@@ -17,7 +17,7 @@ func (s *Server) exportConfig(w http.ResponseWriter, r *http.Request) {
 	}
 
 	w.Header().Set("Content-Type", "application/x-yaml")
-	w.Header().Set("Content-Disposition", "attachment; filename=docker-watcher.yaml")
+	w.Header().Set("Content-Disposition", "attachment; filename=tinyforge.yaml")
 	w.WriteHeader(http.StatusOK)
 	w.Write(data)
 }