fix(cortex-cli): deduplicate agents by name in JSON output

Fixes bounty issue #1203

When an agent is defined in multiple sources (builtin, personal, project),
the agent list JSON output previously showed all duplicates. Now the
load_all_agents() function uses a HashMap to deduplicate agents by name,
with later sources taking precedence: project > personal > builtin.

This ensures users see only one entry per agent name, with their custom
definitions correctly overriding built-in agents.

Author: factorydroid

cortex-cli/src/agent_cmd.rs

@@ -359,26 +359,34 @@ fn get_project_agents_dir() -> Option<PathBuf> {
 }
 
 /// Load all agents from various sources.
+///
+/// Agents are loaded in order: builtin -> personal -> project.
+/// When an agent with the same name exists in multiple sources,
+/// the later source takes precedence (project > personal > builtin).
 fn load_all_agents() -> Result<Vec<AgentInfo>> {
-    let mut agents = Vec::new();
+    let mut agents_map: HashMap<String, AgentInfo> = HashMap::new();
 
-    // Load built-in agents
-    agents.extend(load_builtin_agents());
+    // Load built-in agents first (lowest priority)
+    for agent in load_builtin_agents() {
+        agents_map.insert(agent.name.clone(), agent);
+    }
 
-    // Load personal agents from ~/.cortex/agents/
+    // Load personal agents from ~/.cortex/agents/ (overrides builtin)
     let personal_dir = get_agents_dir()?;
     if personal_dir.exists() {
-        let personal_agents = load_agents_from_dir(&personal_dir, AgentSource::Personal)?;
-        agents.extend(personal_agents);
+        for agent in load_agents_from_dir(&personal_dir, AgentSource::Personal)? {
+            agents_map.insert(agent.name.clone(), agent);
+        }
     }
 
-    // Load project agents from .cortex/agents/
+    // Load project agents from .cortex/agents/ (highest priority, overrides all)
     if let Some(project_dir) = get_project_agents_dir() {
-        let project_agents = load_agents_from_dir(&project_dir, AgentSource::Project)?;
-        agents.extend(project_agents);
+        for agent in load_agents_from_dir(&project_dir, AgentSource::Project)? {
+            agents_map.insert(agent.name.clone(), agent);
+        }
     }
 
-    Ok(agents)
+    Ok(agents_map.into_values().collect())
 }
 
 /// Load built-in agents.
@@ -1687,4 +1695,72 @@ This is the system prompt.
         let result = format_color_with_preview("invalid");
         assert_eq!(result, "invalid");
     }
+
+    #[test]
+    fn test_agent_deduplication_by_name() {
+        // Simulate the deduplication logic used in load_all_agents()
+        let builtin_agent = AgentInfo {
+            name: "build".to_string(),
+            display_name: Some("Build".to_string()),
+            description: Some("Builtin build agent".to_string()),
+            mode: AgentMode::Primary,
+            native: true,
+            hidden: false,
+            prompt: None,
+            temperature: None,
+            top_p: None,
+            color: Some("#22c55e".to_string()),
+            model: None,
+            tools: HashMap::new(),
+            allowed_tools: None,
+            denied_tools: Vec::new(),
+            max_turns: None,
+            can_delegate: true,
+            tags: vec!["development".to_string()],
+            source: AgentSource::Builtin,
+            path: None,
+        };
+
+        let personal_agent = AgentInfo {
+            name: "build".to_string(), // Same name as builtin
+            display_name: Some("Custom Build".to_string()),
+            description: Some("Personal build agent override".to_string()),
+            mode: AgentMode::Primary,
+            native: false,
+            hidden: false,
+            prompt: Some("Custom prompt".to_string()),
+            temperature: Some(0.5),
+            top_p: None,
+            color: Some("#ff0000".to_string()),
+            model: None,
+            tools: HashMap::new(),
+            allowed_tools: None,
+            denied_tools: Vec::new(),
+            max_turns: None,
+            can_delegate: true,
+            tags: vec!["custom".to_string()],
+            source: AgentSource::Personal,
+            path: Some(PathBuf::from("/home/user/.cortex/agents/build.md")),
+        };
+
+        // Test deduplication: later source should override earlier
+        let mut agents_map: HashMap<String, AgentInfo> = HashMap::new();
+        agents_map.insert(builtin_agent.name.clone(), builtin_agent);
+        agents_map.insert(personal_agent.name.clone(), personal_agent);
+
+        let agents: Vec<_> = agents_map.into_values().collect();
+
+        // Should have only one agent named "build"
+        let build_agents: Vec<_> = agents.iter().filter(|a| a.name == "build").collect();
+        assert_eq!(build_agents.len(), 1);
+
+        // The personal agent should have overridden the builtin
+        let build = build_agents[0];
+        assert_eq!(build.source, AgentSource::Personal);
+        assert_eq!(
+            build.description,
+            Some("Personal build agent override".to_string())
+        );
+        assert!(!build.native);
+    }
 }