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/config/config.go

@@ -1,4 +1,4 @@
-// Package config loads smartrund's runtime infrastructure configuration
+// Package config loads geniusrund's runtime infrastructure configuration
 // from environment variables (paths and process settings that don't belong
 // in the user-editable profile). Garmin credentials and every tunable
 // analysis-engine parameter live in the profile (internal/store.Profile)
@@ -12,7 +12,7 @@ import (
 	"time"
 )
 
-// Config holds smartrund's process-level configuration.
+// Config holds geniusrund's process-level configuration.
 type Config struct {
 	// Addr is the HTTP listen address, e.g. ":8080".
 	Addr string
@@ -35,13 +35,13 @@ type Config struct {
 // for anything optional. Returns an error if a required variable is unset.
 func Load() (Config, error) {
 	cfg := Config{
-		Addr:                 getEnvDefault("SMARTRUN_ADDR", ":8080"),
-		DBPath:               getEnvDefault("SMARTRUN_DB_PATH", "smartrun.db"),
+		Addr:                 getEnvDefault("GENIUSRUN_ADDR", ":8080"),
+		DBPath:               getEnvDefault("GENIUSRUN_DB_PATH", "geniusrun.db"),
 		GarminPythonPath:     os.Getenv("MCP_GARMIN_PYTHON"),
 		GarminServerPath:     os.Getenv("MCP_GARMIN_SERVER"),
 		GarminTokenStore:     os.Getenv("GARMIN_TOKENSTORE"),
-		MinConfidence:        getEnvFloat("SMARTRUN_MIN_CONFIDENCE", 0.6),
-		IncrementalSyncEvery: getEnvDuration("SMARTRUN_INCREMENTAL_SYNC_EVERY", 6*time.Hour),
+		MinConfidence:        getEnvFloat("GENIUSRUN_MIN_CONFIDENCE", 0.6),
+		IncrementalSyncEvery: getEnvDuration("GENIUSRUN_INCREMENTAL_SYNC_EVERY", 6*time.Hour),
 	}
 
 	if cfg.GarminPythonPath == "" {