PR 33935 real dev verification
main: 17a6a01d84e3adf9f29df2639d6b6079a434e1b2
head: a28cc8a42e7157aefffd5ade7cffaf1233f66b44
Linux Boat VM, /usr/bin/google-chrome, repository Playwright 1.60.0.
vp i on both checkouts. One background dev server at a time.
main server/web: 16733/8693; PR server/web: 13773/5733.
Data: project and two threads created using the web client. Codex gpt-6.1-sol completed real turns through the local provider proxy. Tool calls read actual repository source. No fixture, mock or database insertion. Isolated development state copied after main stopped.

$ node /tmp/server-load.cjs main-neighbor 16733 <neighbor-thread-id>
5 idle bounded reads, 7 batches of 8 concurrent transcript exports + a neighboring-thread bounded read.
All 56 exports HTTP 200, each 2,037,213 bytes.
Neighbor bounded idle median: 146 ms. Under export load: 633 ms.
6 aborted exports: AbortError. Later export: HTTP 200, 2,037,213 bytes.

$ node /tmp/server-load.cjs pr-neighbor 13773 <same-neighbor-thread-id>
Same data, requests, and sample counts.
All 56 exports HTTP 200, each 2,037,213 bytes.
Neighbor bounded idle median: 86 ms. Under export load: 283 ms.
6 aborted exports: AbortError. Later export: HTTP 200, 2,037,213 bytes.

PR failure recovery: 8 concurrent nonexistent-thread transcript requests returned 404; next valid export returned 200, 2,037,213 bytes.
Web UI: sidebar navigation to neighboring thread and back completed during 8 concurrent exports. A single click-to-message-visible sample was 1384 ms on main and 2023 ms on PR. This does NOT demonstrate an end-to-end UI speedup. The server read result above is narrower; runs are sequential and head predates current main.
After load, a fresh Codex gpt-6.1-sol turn returned 'provider still works.' in the actual web client.

$ blacksmith-check run --id <task-worker> 'vp run check:changed <PR-parent>'
PASS format, lint, knip, GraphQL, typecheck (3 packages), tests (29 tests across 2 files, including all 27 ThreadManagementService tests).
Source worktree remains clean. No code changes or pushes.

Not verified: cross-environment drag/drop import end-to-end, relay/tunnel, native desktop/mobile, Windows/macOS, 19+ MB exports, oversized-transcript rejection, and a reliable whole-UI performance improvement. The server's real transcript/bounded HTTP paths were exercised directly with the browser's authenticated session and protocol header.