## Evidence

Real server and web client on each commit, fresh synthetic state, Chromium 1280×800/light theme, HTTP caching enabled. Upload and send a deterministic 5,275,501-byte PNG; wait for the committed attachment; reload. Then close and relaunch Chromium five times with the same disk profile at 5 Mbps / 120 ms, avoiding a minting-window boundary. Separately reopen across a real five-minute boundary and inspect fresh HTTP headers. On Pixel 9 / Android API 36 (1080×2424/light theme), inject one committed-image HTTP 503 and let the automatic retry recover.

| Evidence | Before: [5cff012416](https://github.com/pingdotgg/t3code/commit/5cff012416c25e6b88d7f61036171e47729c3f18) | After: [820de993bf](https://github.com/pingdotgg/t3code/commit/820de993bf68e6bd9c695e5f7ea3294caed7cb13) |
| --- | --- | --- |
| Reload | URL changed; 5,275,501 image bytes downloaded. ![Before reload](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/696d001441846fd2/001-committed-image-after-reload.png) | Identical URL; zero transferred bytes. ![After reload](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/60a6549a9db29b16/001-committed-image-after-reload.png) |
| Reload recording | [Before recording](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/e10b39ad0e22de69/web-before.mp4) | [After recording](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/6d9c6ed4b343c43c/web-after.mp4) |
| Browser process restart | ![Before: disk-profile restart downloads image](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/16f117476f7c5932/restart-before-1.png); [Before restart recording](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/3d324e2e794531e3/restart-before.mp4) | ![After: disk-profile restart uses disk cache](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/bd9a283e6660789d/restart-after-1.png); [After restart recording](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/ec07652d16457e62/restart-after.mp4) |
| Five restart samples | Median visible **42.048 s**; median image fetch **8.596 s**; 5.28 MB per reopen. | Median visible **33.669 s**; median image load **17 ms**; zero bytes on all five reopens. |
| Fresh response header | `max-age=3600`, about 3599 s left. ![Before: freshness exceeds remaining token lifetime](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/0b7889836b9f63d7/boundary-before.png) | `max-age=3524`, about 3525 s left. ![After: freshness bounded by remaining token lifetime](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/f1faf1542cb5b506/boundary-after.png) |
| Real five-minute boundary | URL changes and image downloads; [Before boundary recording](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/5122710cb32e37d0/boundary-before.mp4). | URL changes and image downloads after crossing 23:50; [After boundary recording](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/443a0b6a3eb61faa/boundary-after.mp4). ![After: renewed URL and bounded cache age across boundary](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/db471b40355a9457/boundary-crossed-after.png) |
| Android automatic image retry | One injected 503 → different URI → 200 → image visible. [Before retry recording](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/203c043a8bc97e1a/mobile-before.mp4) ![Before: image recovered after retry](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/f7ca5999b4e8f52f/mobile-before.png) | One injected 503 → **identical URI** → 200 → image visible. [After retry recording](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/06b66b8ecbdb2ad0/mobile-after.mp4) ![After: same-URI retry recovered](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/916dd07f25531cc8/mobile-after.png) |

[Scenario file](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/05039efdda393571/scenario.e2e.ts) · [Synthetic seed driver](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/cf87dd8d2fb45ebd/seed.ts) · [Restart driver](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/c293a8615e00fe7d/cache-restart-driver.ts) · [Boundary driver](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/d682298ada5936ce/capture-boundary.ts) · [Failure injection proxy](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/ab033895f1b9ef3a/retry-proxy.mjs)

[All timing measurements](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/9f931151fca8b52f/restart-measurements.json) · [Base boundary/header transcript](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/f55967ef8898d165/boundary-before.json) · [Head boundary/header transcript](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/8aec35e352c805a6/boundary-after.json) · [Base retry transcript](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/a4160b79167f6411/mobile-before-network.jsonl) · [Head retry transcript](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/9589c6b2616f5117/mobile-after-network.jsonl) · [Environment and reproduction notes](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/aa27559418f65366/README.md)

The 2.1 s versus 12.8 s / 6.0× title claim was **not reproduced**. These sequential development-build batches measured 42.048 s versus 33.669 s (1.25×); Vite module loading dominates. The core scenario failed on base and passed on head. The extended base runner timed out after saving its five samples; those values were recovered from the screenshots, and boundary/mobile proof was completed manually. The replay provider rejects the image prompt after the message and attachment commit, so both clients show the same provider error; this does not prevent image cache or retry verification. Android retry clips retain failure/recovery and omit unrelated navigation.

The optional `reuseUrl` field **extends the contract**. Older clients that omit it keep per-mint URLs; the previous older-mobile retry tradeoff is stale. [Corrected description](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/e40aab68e5824dae/proposed-description.md) and [Suggested title](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/fbe3623691a25663/proposed-title.txt) are supplied for the pipeline; no PR metadata was edited.

AI-assisted; verified with the tests and tools listed above.

All restart captures:

Before: [Sample 1](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/16f117476f7c5932/restart-before-1.png) · [Sample 2](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/48e0b38d7a7cf265/restart-before-2.png) · [Sample 3](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/ce68ff1513794276/restart-before-3.png) · [Sample 4](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/fc572f0ae848663d/restart-before-4.png) · [Sample 5](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/c86bc41613ef21f4/restart-before-5.png)

After: [Sample 1](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/bd9a283e6660789d/restart-after-1.png) · [Sample 2](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/7884126f7f4cb7db/restart-after-2.png) · [Sample 3](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/dfb82c944defaaa1/restart-after-3.png) · [Sample 4](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/e87b564ce3ec8c77/restart-after-4.png) · [Sample 5](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/a8ad8f19cb5400ce/restart-after-5.png)

[Sanitized execution logs](https://gh-file-drop-api-prod-mi5fy3sowv63ufte.pinglabs.workers.dev/f/71aadfd08ebcb9d0/sanitized-run-logs-v2.tar.gz)