fix(desktop): resolve all remaining P1 defects (P1-02/05/06, P1-01 experimental)

- P1-02: Heartbeat auto-initialized in kernel_init for default agent
- P1-05: CloneManager shows warning when deleting active agent + auto-switch
- P1-06: AgentInfo returns soul/system_prompt/temperature/max_tokens
- P1-01: Browser Hand marked experimental (requires Fantoccini bridge)
- Updated DEFECT_LIST.md: all P1 resolved (0 active)
- Updated RELEASE_READINESS.md: all P1 sections reflect current status

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

@@ -250,7 +250,7 @@ impl HeartbeatEngine {
     }
 
     /// Restore heartbeat history from VikingStorage metadata (called during init)
-    async fn restore_history(&self) {
+    pub async fn restore_history(&self) {
         let key = format!("heartbeat:history:{}", self.agent_id);
         match crate::viking_commands::get_storage().await {
             Ok(storage) => {
@@ -730,7 +730,7 @@ pub async fn heartbeat_init(
 
 /// Restore the last interaction timestamp for an agent from VikingStorage.
 /// Called during heartbeat_init so the idle-greeting check works after restart.
-async fn restore_last_interaction(agent_id: &str) {
+pub async fn restore_last_interaction(agent_id: &str) {
     let key = format!("heartbeat:last_interaction:{}", agent_id);
     match crate::viking_commands::get_storage().await {
         Ok(storage) => {

desktop/src-tauri/src/kernel_commands/lifecycle.rs

@@ -4,6 +4,9 @@ use serde::{Deserialize, Serialize};
 use tauri::State;
 
 use super::{KernelState, SchedulerState};
+use crate::intelligence::heartbeat::{HeartbeatEngine, HeartbeatEngineState};
+
+const DEFAULT_HEARTBEAT_AGENT: &str = "zclaw-main";
 
 // ---------------------------------------------------------------------------
 // Request / Response types
@@ -59,6 +62,7 @@ pub struct KernelStatusResponse {
 pub async fn kernel_init(
     state: State<'_, KernelState>,
     scheduler_state: State<'_, SchedulerState>,
+    heartbeat_state: State<'_, HeartbeatEngineState>,
     config_request: Option<KernelConfigRequest>,
 ) -> Result<KernelStatusResponse, String> {
     let mut kernel_lock = state.lock().await;
@@ -193,6 +197,20 @@ pub async fn kernel_init(
         *sched_lock = Some(scheduler);
     }
 
+    // Auto-initialize heartbeat engine for the default agent
+    {
+        let mut engines = heartbeat_state.lock().await;
+        if !engines.contains_key(DEFAULT_HEARTBEAT_AGENT) {
+            let agent_id = DEFAULT_HEARTBEAT_AGENT.to_string();
+            let engine = HeartbeatEngine::new(agent_id.clone(), None);
+            crate::intelligence::heartbeat::restore_last_interaction(&agent_id).await;
+            engine.restore_history().await;
+            engine.start().await;
+            engines.insert(agent_id, engine);
+            tracing::info!("[kernel_init] Heartbeat engine auto-initialized and started for '{}'", DEFAULT_HEARTBEAT_AGENT);
+        }
+    }
+
     Ok(KernelStatusResponse {
         initialized: true,
         agent_count,