Playwright diagnostic retention imposes an unintended lifetime browser cutoff #772

The native browser network still encounters an unintended lifetime cutoff in the safe-bash diagnostic observer.

In observePlaywrightCapabilities, monotonically increasing bytes and count charge request postData and response/console metadata against maxCommandBytes and 4,096 events. Navigation clears some displayed records but never restores this budget. Exceeding the diagnostic budget sets permanent state.failure; subsequent console flushes fail otherwise successful browser commands.

Concrete evidence from the consumer native conformance fixture:

• Direct @cloudflare/playwright@1.3.6, without the safe-bash controller, successfully sends 33 printable 2 MiB requests to a local HTTP server: 69,206,016 bytes in about 6.1 seconds.
• The same browser flow through the public safe-bash controller fails with Playwright event retention limit exceeded.
• This is independent of the removed Worker request proxy and is not a Cloudflare traffic limit.

Required correction: bound retained diagnostic history through rolling eviction, retaining standard request/console behavior and per-command output limits. Recording history must not permanently poison the session or stop normal browser traffic. Cover navigation, oversized diagnostic entries, request/response pairs, closed pages and sustained event streams.

This task is implementing the fix in its existing isolated poe-code worktree. The previous release is already publishing, so this correction will require a follow-up verified public release before consumer delivery.