fix: 4 pre-release bug fixes — identity override, model config, agent sync, auto-identity

P1: identity.rs get_identity() returns empty soul/instructions for agents
without explicit identity files. This prevents the default ZCLAW personality
from overriding agent_config.system_prompt. New get_identity_or_default()
method added for the DEFAULT agent.

P2: messaging.rs now uses agent_config.model.model when available, falling
back to global Kernel config. This allows per-agent model selection.

P2: agentStore.ts loadClones retries up to 3 times (300ms interval) when
getClient() returns null, handling the coordinator initialization race.

P2: agent_create Tauri command auto-populates identity files (soul +
instructions) from creation parameters, ensuring build_system_prompt()
has content for new agents.

Also fixes conversationStore upsertActiveConversation to persist generated
conversation IDs, preventing duplicate entries on new conversations.

desktop/src-tauri/src/intelligence/identity.rs

@@ -221,13 +221,39 @@ impl AgentIdentityManager {
         }
     }
 
-    /// Get identity files for an agent (creates default if not exists)
+    /// Get identity files for an agent.
+    ///
+    /// Returns empty soul/instructions for agents without explicit identity files.
+    /// This ensures `build_system_prompt()` returns an empty string when no
+    /// identity has been configured, allowing `agent_config.system_prompt` to
+    /// take precedence via the `system_prompt_override` flow in `messaging.rs`.
+    ///
+    /// The default soul/instructions are only used when explicitly requested
+    /// via `get_identity_or_default()` (e.g., for the DEFAULT agent).
     pub fn get_identity(&mut self, agent_id: &str) -> IdentityFiles {
         if let Some(existing) = self.identities.get(agent_id) {
             return existing.clone();
         }
 
-        // Initialize with defaults
+        // Return empty identity — do NOT auto-populate with defaults.
+        // The identity system should be opt-in: only agents with explicit
+        // SOUL.md / USER.md files get identity-based prompts.
+        let empty = IdentityFiles {
+            soul: String::new(),
+            instructions: String::new(),
+            user_profile: default_user_profile(),
+            heartbeat: None,
+        };
+        empty
+    }
+
+    /// Get identity files for an agent, falling back to defaults.
+    /// Used for the DEFAULT ZCLAW agent which should always have a personality.
+    pub fn get_identity_or_default(&mut self, agent_id: &str) -> IdentityFiles {
+        if let Some(existing) = self.identities.get(agent_id) {
+            return existing.clone();
+        }
+
         let defaults = IdentityFiles {
             soul: default_soul(),
             instructions: default_instructions(),
@@ -741,9 +767,20 @@ mod tests {
     use super::*;
 
     #[test]
-    fn test_get_identity_creates_default() {
+    fn test_get_identity_returns_empty_for_new_agent() {
         let mut manager = AgentIdentityManager::new();
-        let identity = manager.get_identity("test-agent");
+        let agent_id = format!("test-empty-{}", std::process::id());
+        let identity = manager.get_identity(&agent_id);
+        // New agents without explicit identity files should have empty soul/instructions
+        assert!(identity.soul.is_empty());
+        assert!(identity.instructions.is_empty());
+    }
+
+    #[test]
+    fn test_get_identity_or_default_creates_default() {
+        let mut manager = AgentIdentityManager::new();
+        let agent_id = format!("test-default-{}", std::process::id());
+        let identity = manager.get_identity_or_default(&agent_id);
         assert!(!identity.soul.is_empty());
         assert!(!identity.instructions.is_empty());
     }
@@ -751,16 +788,18 @@ mod tests {
     #[test]
     fn test_update_user_profile() {
         let mut manager = AgentIdentityManager::new();
-        manager.update_user_profile("test-agent", "New profile content");
-        let identity = manager.get_identity("test-agent");
+        let agent_id = format!("test-profile-{}", std::process::id());
+        manager.update_user_profile(&agent_id, "New profile content");
+        let identity = manager.get_identity(&agent_id);
         assert_eq!(identity.user_profile, "New profile content");
     }
 
     #[test]
     fn test_proposal_flow() {
         let mut manager = AgentIdentityManager::new();
+        let agent_id = format!("test-proposal-{}", std::process::id());
         let proposal = manager.propose_change(
-            "test-agent",
+            &agent_id,
             IdentityFile::Soul,
             "New soul content",
             "Test proposal",
@@ -775,17 +814,18 @@ mod tests {
         let result = manager.approve_proposal(&proposal.id);
         assert!(result.is_ok());
 
-        let identity = manager.get_identity("test-agent");
+        let identity = manager.get_identity(&agent_id);
         assert_eq!(identity.soul, "New soul content");
     }
 
     #[test]
     fn test_snapshots() {
         let mut manager = AgentIdentityManager::new();
-        manager.update_user_profile("test-agent", "First update");
-        manager.update_user_profile("test-agent", "Second update");
+        let agent_id = format!("test-snapshots-{}", std::process::id());
+        manager.update_user_profile(&agent_id, "First update");
+        manager.update_user_profile(&agent_id, "Second update");
 
-        let snapshots = manager.get_snapshots("test-agent", 10);
+        let snapshots = manager.get_snapshots(&agent_id, 10);
         assert!(snapshots.len() >= 2);
     }
 }