Forward chatId on chat selection notifications

The bridge's outbound handler now prefers an explicit data.chatId
(supplied by the webview after the per-chat scoping fix) when
forwarding chat/selectedModelChanged, chat/selectedAgentChanged, and
chat/selectedVariantChanged to the remote REST endpoints, falling
back to ctx.getCurrentChatId() when the webview omits it. Forward-
compatible: works against both the previous webview submodule (which
did not emit chatId) and the new one.

Bumps eca-webview submodule to pick up the matching webview-side
changes (Phase A drops the 'EMPTY' chat-id sentinel and mints a UUID
upfront; Phase B includes chatId in the host messages and applies
config/updated per-chat when scoped).

editor-code-assistant/eca-emacs#231

🤖 Generated with [eca](https://eca.dev)

Co-Authored-By: eca-agent <git@eca.dev>

Author: ericdallo

eca-webview

@@ -104,17 +104,19 @@ export async function handleOutbound(
         await api.answerQuestion(data.requestId, data.answer, data.cancelled);
         break;
 
-      // --- Config changes (apply to current chat) ---
+      // --- Config changes (apply to the chat the webview targets, falling
+      //     back to the current chat for older webview versions that don't
+      //     forward chatId in the message). ---
       case 'chat/selectedModelChanged':
-        await withCurrentChat(ctx, (chatId) => api.changeModel(chatId, data.model));
+        await withTargetChat(ctx, data.chatId, (chatId) => api.changeModel(chatId, data.model));
         break;
 
       case 'chat/selectedAgentChanged':
-        await withCurrentChat(ctx, (chatId) => api.changeAgent(chatId, data.agent));
+        await withTargetChat(ctx, data.chatId, (chatId) => api.changeAgent(chatId, data.agent));
         break;
 
       case 'chat/selectedVariantChanged':
-        await withCurrentChat(ctx, (chatId) => api.changeVariant(chatId, data.variant));
+        await withTargetChat(ctx, data.chatId, (chatId) => api.changeVariant(chatId, data.variant));
         break;
 
       // --- Editor operations ---
@@ -303,14 +305,17 @@ async function handleUserPrompt(data: UserPromptData, ctx: OutboundContext): Pro
 }
 
 /**
- * Run an action against the current chat ID, silently catching errors.
- * Used for config changes (model/agent/variant) which are best-effort.
+ * Run an action against an explicit chat ID when the webview provides one,
+ * otherwise fall back to the current session-wide chat ID. Errors are
+ * silently caught — these config changes (model/agent/variant) are
+ * best-effort and must not break the UI.
  */
-async function withCurrentChat(
+async function withTargetChat(
   ctx: OutboundContext,
+  explicitChatId: string | undefined,
   action: (chatId: string) => Promise<void>,
 ): Promise<void> {
-  const chatId = ctx.getCurrentChatId();
+  const chatId = explicitChatId || ctx.getCurrentChatId();
   if (chatId) {
     await action(chatId).catch(() => {});
   }

src/bridge/outbound-handler.ts

@@ -249,9 +249,9 @@ export type OutboundMessage =
   | { type: 'chat/removeFlag'; data: { chatId: string; contentId: string } }
   | { type: 'chat/fork'; data: { chatId: string; contentId: string } }
   | { type: 'chat/answerQuestion'; data: { requestId: string; answer: string | null; cancelled: boolean } }
-  | { type: 'chat/selectedModelChanged'; data: { model: string } }
-  | { type: 'chat/selectedAgentChanged'; data: { agent: string } }
-  | { type: 'chat/selectedVariantChanged'; data: { variant: string } }
+  | { type: 'chat/selectedModelChanged'; data: { model: string; chatId?: string; variant?: string } }
+  | { type: 'chat/selectedAgentChanged'; data: { agent: string; chatId?: string } }
+  | { type: 'chat/selectedVariantChanged'; data: { variant: string; chatId?: string } }
   | { type: 'editor/openUrl'; data: { url: string } }
   | { type: 'editor/openFile'; data: unknown }
   | { type: 'editor/openGlobalConfig'; data: unknown }