fix: address PR #62 review findings

- Remove duplicate flag.Parse() call
- Fix nil map panic in LoadRemotePersonas error path by assigning
  empty map when LoadRemotePersonas returns an error
- Tighten isNotFoundError to only check HTTP 404 (remove broad
  'not found' substring check to avoid false positives)
- Clean up personaErr variable scope using narrower-scoped err variables
- Add proper doc comment to LoadRemotePersonasFromPath (Go convention)
- Add file count cap (50 files) in LoadRemotePersonasFromPath to
  prevent resource exhaustion from repos with thousands of small files
- Update test expectation for tightened isNotFoundError

cmd/review-bot/main.go

@@ -79,7 +79,6 @@ func main() {
 	aicoreAPIURL := flag.String("aicore-api-url", envOrDefault("AICORE_API_URL", ""), "SAP AI Core API URL (for provider=aicore)")
 	aicoreResourceGroup := flag.String("aicore-resource-group", envOrDefault("AICORE_RESOURCE_GROUP", "default"), "SAP AI Core resource group (for provider=aicore)")
 
-	flag.Parse()
 	flag.Parse()
 
 	if *versionFlag {
@@ -119,7 +118,6 @@ func main() {
 	// Persona loading is deferred until after giteaClient is initialized,
 	// so we can try loading from the target repo first.
 	var persona *review.Persona
-	var personaErr error
 
 	// Validate reviewer-name: only safe characters allowed in sentinel
 	if err := validateReviewerName(*reviewerName); err != nil {
@@ -184,6 +182,8 @@ func main() {
 		remotePersonas, err := review.LoadRemotePersonas(ctx, fetcher, owner, repoName)
 		if err != nil {
 			slog.Warn("could not load remote personas", "repo", fmt.Sprintf("%s/%s", owner, repoName), "error", err)
+			// Assign empty map so the lookup below doesn't panic
+			remotePersonas = map[string]*review.Persona{}
 		}
 
 		if p, ok := remotePersonas[*personaName]; ok {
@@ -191,9 +191,10 @@ func main() {
 			slog.Info("loaded persona from target repo", "persona", persona.Name, "display", persona.DisplayName)
 		} else {
 			// Fall back to built-in persona
-			persona, personaErr = review.LoadBuiltinPersona(*personaName)
-			if personaErr != nil {
-				slog.Error("failed to load persona", "persona", *personaName, "error", personaErr)
+			var err error
+			persona, err = review.LoadBuiltinPersona(*personaName)
+			if err != nil {
+				slog.Error("failed to load persona", "persona", *personaName, "error", err)
 				os.Exit(1)
 			}
 			slog.Info("loaded built-in persona", "persona", persona.Name, "display", persona.DisplayName)
@@ -204,9 +205,10 @@ func main() {
 			slog.Error("invalid persona-file path", "error", err)
 			os.Exit(1)
 		}
-		persona, personaErr = review.LoadPersona(resolvedPath)
-		if personaErr != nil {
-			slog.Error("failed to load persona file", "file", *personaFile, "error", personaErr)
+		var err2 error
+		persona, err2 = review.LoadPersona(resolvedPath)
+		if err2 != nil {
+			slog.Error("failed to load persona file", "file", *personaFile, "error", err2)
 			os.Exit(1)
 		}
 		slog.Info("loaded persona from file", "file", *personaFile, "persona", persona.Name)