teamchong 102a0966f5 transform: add determinism test + unknown-tag canary ...

Two cheap guardrails based on architectural review:

1. Determinism test: renders the same input twice and asserts byte
   equality of the produced PNGs. Without this guarantee, identical
   system prompts on consecutive turns would yield different image
   bytes, silently destroying the cache hit rate that justifies the
   whole proxy. The test currently passes — locking it in so a future
   refactor can't regress it without noticing.

2. Unknown-tag canary: splitStaticDynamic now sniffs the *static* slab
   for any <tag>...</tag>-shaped block whose name isn't in
   DYNAMIC_BLOCK_TAGS. Surfaced via info.unknownStaticTags and emitted
   on the tracker event as unknown_static_tags. If Claude Code ships a
   new per-turn tag in a future release, it'll show up in logs within
   hours instead of being silently baked into the cached image (where
   it would tank cache hit rate with no error).

Also adds tracker.ts (Tracker interface, TrackEvent shape,
JsonLogTracker, noopTracker, toTrackEvent normalizer). Hosts will wire
these in the next commit.

2026-05-18 16:05:48 -04:00

..

proxy-usage.test.ts

proxy: tee upstream body and extract Anthropic usage tokens

2026-05-18 16:02:52 -04:00

render.test.ts

transform: add determinism test + unknown-tag canary

2026-05-18 16:05:48 -04:00