[futurepaul]

First of the new-chat batch. A new chat waits 1.8 s on POST /api/fragments (80% of the 3.5 s to usable on preview, bench run eb7234c3b3), and nothing says which step takes it. This PR only measures; nothing changes behaviour.

Each route reports its waits in the standard Server-Timing header, <part>;dur=<ms>, using the js::Laps the cell already keeps. That costs one header per response.

• POST /api/fragments:
  • ledger, object, and agent for an agent's create;
  • then the Fragment object's own repo, key, manifest, list, seed and alarm, merged into the same header.
• PUT /api/f/<name>/members/<agent>: identity, list, joined.
• __signin?token= (the frame's sign-in): redeem.
• __live accept: identity, accept.

docs/api.md names the parts. The e2e lanes control, members, frames and live check that each route sends its parts.

Tests: cargo xtask check passes. cargo xtask e2e --only auth,create,lockdown,members,reach,frames,live,channels,chat,signin,shell,watch,share gave 898 passed, 0 failed.

Once this is on preview, I'll rerun the chat bench and report the split.

🤖 Generated with Claude Code

[futurepaul]

Codex review @ 8fb2695: PASS

Checked the affected awaits and error paths: the stamps preserve statuses, bodies, redirect cookies/Location and the 101 WebSocket handle, merge the router/object timings, and leave cached assets untouched. Header values contain only fixed step names and numeric durations, with no identities, names or secrets. The exact-head release build passed at 6,519,278 bytes (80,722 bytes of headroom), and the e2e crate's host unit tests passed (56 passed, one ignored); I did not rerun e2e lanes, and CI check is still running.

[alexlwn123]

Pass — no blocking defects found at 8fb26953309b2de2920c1cab85911ce7bfdc8fc4. Posting COMMENT under the review automation's policy.

Traced creation (including name retries and agent membership), member updates, sign-in redemption, and live acceptance. The timing stamps preserve existing statuses, bodies, redirect cookies/Location and WebSocket handles; router timings are combined with the object's header. The additional timing-test socket publishes no presence, so it does not disturb the existing presence assertions.

Validation on an isolated exact-head checkout:

• cargo test --locked -p fragment-e2e -- --skip hosted::tests: 34 passed, 0 failed, 1 Chrome test ignored, 22 hosted-module tests filtered out. This exercises host unit tests and local HTTP fixtures, not the integration lanes. The hosted module was excluded because this environment documents proxy-denied synthetic recorder hosts.
• In cell/, CARGO_ENCODED_RUSTFLAGS='-Ctarget-feature=+simd128' cargo clippy --locked --target wasm32-unknown-unknown -- -D warnings: passed.
• CI check passed. The PR's green e2e check is a pass-through; its actual shards were skipped.

No real workerd/Cloudflare, container or browser execution was performed in this review. The environment documents unresolved Docker DNS/CA and Chromium sandbox prerequisites; those layers remain unverified. No external vendor services were exercised, and no sandbox/network checks were weakened.