feat: persist GooseMode per-session via session DB (#7854)

Signed-off-by: Adrian Cole <adrian@tetrate.io>

crates/goose/src/gateway/handler.rs

@@ -128,14 +128,19 @@ impl GatewayHandler {
             user.display_name.as_deref().unwrap_or(&user.user_id)
         );
 
+        let config = Config::global();
         let session = self
             .agent_manager
             .session_manager()
-            .create_session(working_dir, session_name, SessionType::Gateway)
+            .create_session(
+                working_dir,
+                session_name,
+                SessionType::Gateway,
+                config.get_goose_mode().unwrap_or_default(),
+            )
             .await?;
 
         let manager = self.agent_manager.session_manager();
-        let config = Config::global();
 
         // Store the current provider and model config on the session so the agent
         // can be restored after LRU eviction, matching the start_agent flow.
@@ -197,6 +202,7 @@ impl GatewayHandler {
         let current_provider = config.get_goose_provider().ok();
         let current_model_name = config.get_goose_model().ok();
         let current_extensions = get_enabled_extensions();
+        let current_mode = config.get_goose_mode().unwrap_or_default();
 
         // --- what the session has ---
         let session_extensions: Vec<ExtensionConfig> =
@@ -208,8 +214,9 @@ impl GatewayHandler {
         let model_changed = current_model_name.as_deref()
             != session.model_config.as_ref().map(|m| m.model_name.as_str());
         let extensions_changed = current_extensions != session_extensions;
+        let mode_changed = current_mode != session.goose_mode;
 
-        if !provider_changed && !model_changed && !extensions_changed {
+        if !provider_changed && !model_changed && !extensions_changed && !mode_changed {
             return Ok(false);
         }
 
@@ -218,6 +225,7 @@ impl GatewayHandler {
             provider_changed,
             model_changed,
             extensions_changed,
+            mode_changed,
             "syncing gateway session with current config"
         );
 
@@ -242,6 +250,10 @@ impl GatewayHandler {
             }
         }
 
+        if mode_changed {
+            update = update.goose_mode(current_mode);
+        }
+
         update.apply().await?;
         Ok(extensions_changed)
     }