feat(browser): prefer Chrome default + add Brave/Edge fallbacks

Co-authored-by: Christoph Nakazawa <christoph.pojer@gmail.com>

src/agents/subagent-announce.format.test.ts

@@ -54,7 +54,9 @@ describe("subagent announce formatting", () => {
     });
 
     expect(agentSpy).toHaveBeenCalled();
-    const call = agentSpy.mock.calls[0]?.[0] as { params?: { message?: string; sessionKey?: string } };
+    const call = agentSpy.mock.calls[0]?.[0] as {
+      params?: { message?: string; sessionKey?: string };
+    };
     const msg = call?.params?.message as string;
     expect(call?.params?.sessionKey).toBe("agent:main:main");
     expect(msg).toContain("background task");

src/agents/subagent-registry.persistence.test.ts

@@ -119,7 +119,8 @@ describe("subagent registry persistence", () => {
     // announce should NOT be called since cleanupHandled was true
     const calls = announceSpy.mock.calls.map((call) => call[0]);
     const match = calls.find(
-      (params) => (params as { childSessionKey?: string }).childSessionKey === "agent:main:subagent:two",
+      (params) =>
+        (params as { childSessionKey?: string }).childSessionKey === "agent:main:subagent:two",
     );
     expect(match).toBeFalsy();
   });

src/agents/subagent-registry.store.ts

@@ -38,9 +38,7 @@ export function loadSubagentRegistryFromDisk(): Map<string, SubagentRunRecord> {
     const announceCompletedAt =
       typeof typed.announceCompletedAt === "number" ? typed.announceCompletedAt : undefined;
     const cleanupCompletedAt =
-      typeof typed.cleanupCompletedAt === "number"
-        ? typed.cleanupCompletedAt
-        : announceCompletedAt;
+      typeof typed.cleanupCompletedAt === "number" ? typed.cleanupCompletedAt : announceCompletedAt;
     const cleanupHandled =
       typeof typed.cleanupHandled === "boolean"
         ? typed.cleanupHandled

src/agents/subagent-registry.ts

@@ -214,11 +214,7 @@ function ensureListener() {
   });
 }
 
-function finalizeSubagentCleanup(
-  runId: string,
-  cleanup: "delete" | "keep",
-  didAnnounce: boolean,
-) {
+function finalizeSubagentCleanup(runId: string, cleanup: "delete" | "keep", didAnnounce: boolean) {
   const entry = subagentRuns.get(runId);
   if (!entry) return;
   if (cleanup === "delete") {

src/agents/system-prompt.ts

@@ -442,7 +442,8 @@ export function buildAgentSystemPrompt(params: {
 
   if (extraSystemPrompt) {
     // Use "Subagent Context" header for minimal mode (subagents), otherwise "Group Chat Context"
-    const contextHeader = promptMode === "minimal" ? "## Subagent Context" : "## Group Chat Context";
+    const contextHeader =
+      promptMode === "minimal" ? "## Subagent Context" : "## Group Chat Context";
     lines.push(contextHeader, extraSystemPrompt, "");
   }
   if (params.reactionGuidance) {