fix(proof): count only admitted provider observations

[drewstone]

Reproduced bug

The merged provider-observation loop counted a poll before admitting the deadline.
An already-expired shared deadline produced observerCalls0 and attempts0, but reported polls1.
The single regression fails on main571b25fd with 1 !== null.

Fix

Move the counter immediately before observe(), after deadline admission.
The expired path now retains observerCalls0/attempts0 and pollsnull (unobserved).
An admitted observer still produces observerCalls1/polls1.
Exactly one regression covers this reproduced metric bug.

Scope is only provider-observation.mjs and the existing narrow test file.
Frozen cases, prompts, model, sleep180, cleanup and the default-OFF optimization flag are unchanged.
No app, README, docs, CI or release changes.

Verification

• Single regression: FAIL on unchanged main, PASS after fix.
• Live-required self-check:169/169 PASS.
• Full pnpm run check: PASS, exit0.
• No HTTP/provider call, production credential read, paid call or peer mutation.

This fixes metric truth; it claims no speed gain.
The real protected baseline remains827s full wall/821s runner slot, n=1.
Root owns review, merge and the next signed/protected dispatch.

[tangletools]

✅ Auto-approved PR — 189d3583

Blanket team auto-approval is intentional. The merge gates are CI and codex-p1.
No automated review runs on this PR. This approval rests on the rule above alone.

_{tangletools · auto-approval · reason: blanket_auto_approve · 2026-09-27T04:22:42Z}