feat(ai): bind each conversation to its own connection

packages/app-tests/aiAssistantSendGuard.test.ts

@@ -51,7 +51,10 @@ function functionBody(script: string, signature: string): string {
 test("send() acquires the guard synchronously before the first await", () => {
   const body = functionBody(scriptSetupContent(), "async function send()");
 
-  const entryCheck = body.search(/\|\|\s*isGenerating\.value\)\s*return/);
+  // Anchor on the condition, not on a one-line `return`: the branch may run a
+  // synchronous cleanup first (a declined write-confirmation grant), so the
+  // shape is a block now. The assertions below still require a return inside it.
+  const entryCheck = body.search(/\|\|\s*isGenerating\.value\)\s*\{/);
   const guardSet = body.indexOf("isGenerating.value = true");
   // `await` as a whole word (not the substring inside e.g. the
   // `awaiting_write_confirmation` run status), so the first suspension point is
@@ -61,6 +64,7 @@ test("send() acquires the guard synchronously before the first await", () => {
   assert.notEqual(entryCheck, -1, "send() should early-return when isGenerating is already set");
   assert.notEqual(guardSet, -1, "send() should set the isGenerating guard");
   assert.notEqual(firstAwait, -1, "send() should contain an await");
+  assert.ok(body.slice(entryCheck, guardSet).includes("return"), "the isGenerating branch must return before the guard set");
 
   // The entry check runs first, then the guard is set, then (and only then) the
   // first await suspends. Because nothing awaits between the check and the set,

packages/app-tests/aiMessageLayout.test.ts

@@ -75,7 +75,13 @@ test("AI request failures use localized backend diagnostics", () => {
 test("AI analysis export keeps the connection that produced each assistant response", () => {
   assert.match(source, /sourceConnectionName\?: string/);
   assert.match(source, /const runSourceName = runPluginContext\?\.pluginName \?\? connection\?\.name \?\? ""/);
-  assert.match(source, /runMessages\.push\(\{ role: "assistant", content: "", sourceConnectionName: runSourceName \}\)/);
-  assert.match(source, /connectionName: msg\.sourceConnectionName \?\? props\.connection\?\.name/);
+  // The assistant placeholder must record the connection that produced it. The
+  // literal also carries per-run fields (the frozen `sourceBinding` target,
+  // #9902), so pin the pair instead of the closing brace.
+  assert.match(source, /runMessages\.push\(\{ role: "assistant", content: "", sourceConnectionName: runSourceName,/);
+  assert.match(source, /sourceBinding: runBinding \}\);/);
+  // The fallback for a message that predates `sourceConnectionName` is the
+  // conversation's own bound connection, not whatever tab is visible (#9902).
+  assert.match(source, /connectionName: msg\.sourceConnectionName \?\? boundConnection\.value\?\.name/);
   assert.match(source, /sourceConnectionName: m\.role === "assistant" \? conv\.connectionName : undefined/);
 });