fix(fork): test capture diagnostics through frame fallback

Author: Quicksaver

FORK.md

@@ -849,9 +849,9 @@ The tracked accessory note is [PREVIEW_RECORDING_START.md](PREVIEW_RECORDING_STA
 
 **Worktree branch:** `fix/preview-capture-diagnostics`
 
-The standalone worktree is `E:/Projects/t3code.worktrees/preview-capture-diagnostics`, at HEAD `8d8196e4d2df519519e94ce1e01abba4dd77cd8d` directly above fixed `base/main` `48b71f0eb323d08c8fcadfe54adf34becb2984da`. The clean source branch tracks `origin/fix/preview-capture-diagnostics`; `base/main` remains its comparison base. Its source commit is published and retains all thirteen customization files unchanged. Historical locked-state proof below retains its original source attribution.
+The standalone worktree is `E:/Projects/t3code.worktrees/preview-capture-diagnostics`, at HEAD `104d61b2b1da9417b8879c92f0137b35b083ddd4` above customization baseline `94e03f4dc89c924807797ccf8825b48d1e2d03f3` and fixed `base/main` `c77a7b7eebd6ea8a3a63bbcaaa7c1707fe65c86e`. The clean source branch tracks `origin/fix/preview-capture-diagnostics`; `base/main` remains its comparison base. The capture-message helper is private, removing its unused-export lint defect without changing diagnostics. Historical locked-state proof below retains its original source attribution.
 
-Status is VALID ADAPTED with PASSING actual Windows locked/off acquisition-error diagnostics, cleanup and same-original-guest retry. Incoming agent browser automation moved to the environment server and supersedes old desktop agent/broker propagation. Surviving diagnostics preserve safe typed native screenshot/recording failures through IPC and the direct primary cause through the recording wrapper/UI. Capture, fallback, permissions, power behavior and server-browser CDP are outside this customization; no new CDP proof was produced.
+Status is VALID ADAPTED. Current branch Windows proof covers native tagged failures, renderer decoding, actionable fixture toast presentation, real screenshot and recording, and cleanup. Historical actual locked/off acquisition-error diagnostics and same-original-guest retry retain their recorded source attribution. Incoming agent browser automation moved to the environment server and supersedes old desktop agent/broker propagation. Surviving diagnostics preserve safe typed native screenshot/recording failures through IPC and the direct primary cause through the recording wrapper/UI. Capture, fallback, permissions, power behavior and server-browser CDP are outside this customization; no new CDP proof was produced.
 
 Chronology is fixed `26285ab` to rebased/adapted source and reviewed `85593b3e2f313db3e58ed1ac88fc55c273ca4639`, including the generic-cleanup correction. Genuine locked/display-off Windows `getDisplayMedia` then rejected with `NotReadableError / Could not start video source` after native source grant, but the actual production toast remained generic. That reproduced defect justified the small `14f3cbc` formatter fix. It recognizes the reached `NotReadableError` DOMException only for `capture-media-stream`, including the producer's explicitly stored primary cause if cleanup also fails. It adds unlock/display-on/retry guidance while preserving native name/message, stored causes, generic cleanup wording and recording behavior. The follow-up passed 35 focused recording tests, web typecheck and targeted lint, then actual exact-final actionable-toast, cleanup and retry proof.
 

PREVIEW_CAPTURE_DIAGNOSTICS.md

@@ -2,9 +2,9 @@
 
 This is the tracked text accessory copy for `fix/preview-capture-diagnostics`.
 
-The standalone worktree is `E:/Projects/t3code.worktrees/preview-capture-diagnostics`, at published HEAD `d0df02a17cb872a893341e28b19faed04bd1f770`, directly above pinned `base/main` `43f8a8de17a7ac1baa7a3cf36d681856de2d8add`. It tracks `origin/fix/preview-capture-diagnostics`, with `base/main` as its comparison base. Main combines the diagnostic contract with native screenshots and requester-bound recording. Acquisition tests use that recording path and prove canvas fallback rejection and a fresh-frame retry.
+The standalone worktree is `E:/Projects/t3code.worktrees/preview-capture-diagnostics`, at published HEAD `104d61b2b1da9417b8879c92f0137b35b083ddd4`, preserving baseline `94e03f4dc89c924807797ccf8825b48d1e2d03f3` directly above pinned `base/main` `c77a7b7eebd6ea8a3a63bbcaaa7c1707fe65c86e`. It tracks `origin/fix/preview-capture-diagnostics`, with `base/main` as its comparison base. The private capture-message helper removes an unused-export lint defect without behavior change. Main combines the diagnostic contract with native screenshots and requester-bound recording. Acquisition tests use that recording path and prove canvas fallback rejection and a fresh-frame retry.
 
-Current-source Windows proof covers native tagged failures, renderer decoding, actionable fixture toast presentation, real screenshot and changing native recording, and cleanup. Genuine acquisition rejection, full toolbar/MCP routing and fresh locked/display-off behavior remain unverified on this source. Current receipts and review qualifications are in the worktree's ignored `BRANCH_DETAILS.md`; PR 17244's substantive workflows require maintainer approval.
+Current-source Windows proof covers native tagged failures, renderer decoding, actionable fixture toast presentation, real screenshot and changing native recording, and cleanup. Genuine acquisition rejection, full toolbar/MCP routing and fresh locked/display-off behavior remain unverified on this source. Scoped branch checks and the current-head hosted lint pass. Hosted Typecheck is blocked by a removed ChatView setter in a newer upstream synthetic merge, absent from this pinned source. Current receipts and review qualifications are in the worktree's ignored BRANCH_DETAILS.md. Historical proof below retains its own source attribution.
 
 ## Historical acquisition proof at 26285ab
 

apps/web/src/browser/browserRecording.test.ts

@@ -781,16 +781,20 @@ describe("browser recording", () => {
   });
 
   it.each([false, true])(
-    "explains real video-source rejection and permits retry when cleanup fails: %s",
+    "explains fallback video-source rejection and permits retry when cleanup fails: %s",
     async (cleanupFails) => {
       const cause = new DOMException("Could not start video source", "NotReadableError");
       const cleanupCause = new Error("native stop failed");
-      getDisplayMedia.mockRejectedValueOnce(cause);
+      const frames = prepareFrameFallback();
+      frames.canvas.captureStream.mockImplementationOnce(() => {
+        throw cause;
+      });
       if (cleanupFails) stopScreencast.mockRejectedValueOnce(cleanupCause);
 
-      const error = await startBrowserRecording("recording-tab").catch(
-        (failure: unknown) => failure,
-      );
+      const failed = startBrowserRecording("recording-tab").catch((failure: unknown) => failure);
+      await frames.ready;
+      await frames.receive();
+      const error = await failed;
       expect(error).toMatchObject({
         _tag: "BrowserRecordingOperationError",
         operation: "capture-media-stream",
@@ -806,16 +810,20 @@ describe("browser recording", () => {
       expect(readActiveBrowserRecordingTabIds()).toEqual(new Set());
       expect(useBrowserSurfaceStore.getState().activityByTabId["recording-tab"]).toBeUndefined();
 
-      await startBrowserRecording("recording-tab");
+      const recoveredFrames = prepareFrameFallback();
+      const restarted = startBrowserRecording("recording-tab");
+      await recoveredFrames.ready;
+      await recoveredFrames.receive();
+      await restarted;
       await stopBrowserRecording("recording-tab");
-      expect(getDisplayMedia).toHaveBeenCalledTimes(2);
+      expect(getUserMedia).toHaveBeenCalledTimes(2);
     },
   );
 
   it("keeps unrecognized acquisition failures generic", async () => {
     const cause = new Error("capture failed");
     cause.name = "NotReadableError";
-    getDisplayMedia.mockRejectedValueOnce(cause);
+    getUserMedia.mockRejectedValueOnce(cause);
 
     await expect(startBrowserRecording("recording-tab")).rejects.toMatchObject({
       operation: "capture-media-stream",
@@ -838,13 +846,13 @@ describe("browser recording", () => {
       cause,
       message: cause.message,
     });
-    expect(getDisplayMedia).not.toHaveBeenCalled();
+    expect(getUserMedia).not.toHaveBeenCalled();
     expect(readActiveBrowserRecordingTabIds()).toEqual(new Set());
     expect(useBrowserSurfaceStore.getState().activityByTabId["recording-tab"]).toBeUndefined();
 
     await startBrowserRecording("recording-tab");
     await stopBrowserRecording("recording-tab");
-    expect(getDisplayMedia).toHaveBeenCalledOnce();
+    expect(getUserMedia).toHaveBeenCalledOnce();
   });
 
   it("times out stalled stream acquisition and stops a late stream", async () => {