feat: make LLM timeout configurable (default 5min)

New flag: --llm-timeout / LLM_TIMEOUT (seconds, default 300)
New builder: llmClient.WithTimeout(duration)
Composite action: new timeout input

Keeps 5 minutes as the sensible default but allows tuning for
larger repos or slower models.

cmd/review-bot/main.go

@@ -32,6 +32,7 @@ func main() {
 	patternsFiles := flag.String("patterns-files", envOrDefault("PATTERNS_FILES", "README.md"), "Comma-separated file paths to fetch from patterns repo")
 	dryRun := flag.Bool("dry-run", false, "Print review to stdout instead of posting")
 	llmTemp := flag.Float64("llm-temperature", envOrDefaultFloat("LLM_TEMPERATURE", 0), "LLM temperature (0 = server default)")
+	llmTimeout := flag.Int("llm-timeout", envOrDefaultInt("LLM_TIMEOUT", 300), "LLM request timeout in seconds (default 300)")
 
 	flag.Parse()
 
@@ -65,6 +66,9 @@ func main() {
 	if *llmTemp > 0 {
 		llmClient.WithTemperature(*llmTemp)
 	}
+	if *llmTimeout > 0 {
+		llmClient.WithTimeout(time.Duration(*llmTimeout) * time.Second)
+	}
 
 	// Create a top-level context with a 3-minute timeout for all operations
 	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Minute)
@@ -285,3 +289,13 @@ func envOrDefaultFloat(key string, defaultVal float64) float64 {
 	}
 	return defaultVal
 }
+
+func envOrDefaultInt(key string, defaultVal int) int {
+	if v := os.Getenv(key); v != "" {
+		i, err := strconv.Atoi(v)
+		if err == nil {
+			return i
+		}
+	}
+	return defaultVal
+}