Rename smartrun to geniusrun throughout the codebase

Updates the Go module path, cmd/smartrund -> cmd/geniusrund, the
smartrun-dev skill, .gitignore, and every reference in docs/CLAUDE.md
to match.

backend/internal/api/reclassify.go

@@ -3,7 +3,7 @@ package api
 import (
 	"net/http"
 
-	"smartrun/backend/internal/store"
+	"geniusrun/backend/internal/store"
 )
 
 // handleReclassifyAll re-runs the rule engine for every activity except