feat(settings): tambah hive_mind_node_timeout_ms dengan fallback serde default

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/model/settings.rs

@@ -19,7 +19,10 @@ pub enum InternetMode {
     Full,
 }
 
-
+/// Default per-node timeout for hive-mind nodes: 10 minutes.
+fn default_hive_mind_node_timeout_ms() -> u64 {
+    600_000
+}
 
 /// Top-level application settings, serialized to `settings.json` in the store dir.
 ///
@@ -42,6 +45,11 @@ pub struct Settings {
     pub session_archive_enabled: bool,
     pub lsp_auto_provision: bool,
     pub lsp_languages: Vec<String>,
+    /// Wall-clock deadline for a single hive-mind processing node (cycle
+    /// node or synthesis node). Prevents one stuck node from hanging an
+    /// entire hive-mind convergence forever.
+    #[serde(default = "default_hive_mind_node_timeout_ms")]
+    pub hive_mind_node_timeout_ms: u64,
 }
 
 impl Default for Settings {
@@ -62,6 +70,7 @@ impl Default for Settings {
             session_archive_enabled: true,
             lsp_auto_provision: true,
             lsp_languages: Vec::new(),
+            hive_mind_node_timeout_ms: default_hive_mind_node_timeout_ms(),
         }
     }
 }
@@ -103,3 +112,42 @@ impl Settings {
         Ok(())
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn default_hive_mind_node_timeout_is_ten_minutes() {
+        let settings = Settings::default();
+        assert_eq!(settings.hive_mind_node_timeout_ms, 600_000);
+    }
+
+    #[test]
+    fn missing_hive_mind_node_timeout_field_falls_back_to_default() {
+        // Simulates loading a settings.json written before this field
+        // existed — #[serde(default = ...)] must fill it in rather than
+        // failing the whole parse (which would silently reset every
+        // other saved setting to default too).
+        let old_json = r#"{
+            "internet_mode": "Off",
+            "provider": "zen",
+            "model": "deepseek-v4-flash-free",
+            "api_keys": {},
+            "max_tokens": null,
+            "temperature": null,
+            "review_enabled": true,
+            "review_max_lessons_per_run": 5,
+            "adaptive_review_max_skip": 3,
+            "verify_command": null,
+            "verify_timeout_ms": 30000,
+            "workflow_max_concurrency": 5,
+            "session_archive_enabled": true,
+            "lsp_auto_provision": true,
+            "lsp_languages": []
+        }"#;
+        let parsed: Settings = serde_json::from_str(old_json)
+            .expect("must parse even without the new field present");
+        assert_eq!(parsed.hive_mind_node_timeout_ms, 600_000);
+    }
+}