fix(opencode): only a refusal naming the model clears borrowed tools

[maxmad64bis]

⚠️ base-red inherited: #15306

Summary

Requests that reuse stored tool names lost them after three failures of any kind, so a busy model answered with 429 and the next request went out bare, then drew a 403.

This change counts a refusal only when a 403 or 451 response names the model — every notation site passes such a verdict — and a 200 on reused names clears the refusal streak while the stored entry stays in place.

The stored names now survive 429 answers, and the request after them still carries the working tool shape.

Related Issues

• No linked issue — reproduced on the release base

Validation

• Change type: provider
• Focused tests and category gates from the golden path
• npm run lint
• Reconciled with the current active release base; focused checks rerun afterward
• Production-code changes include a new or updated automated test in this PR

Tests Added Or Updated

• tests/unit/opencode-free-tier-request-contract.test.ts: three 429 answers on reused names keep the stored names, three 403 answers carrying the refusal still clear them after the third, a 200 on reused names resets the streak to one, unrelated refusals never touch the stored names, notes without a verdict never count, and a deferred 403 verdict still counts

Coverage Notes

• open-sse/executors/opencodeFreeTierContract.ts: covered by the request-contract suite (discriminant guard and streak confirmation cases)
• open-sse/executors/opencode.ts: covered by the request-contract, shape-retry, refusal-rotation, and balance shard suites (notification sites)
• open-sse/executors/opencodeRequestShape.ts: covered by the shape-retry suite (verdict read once, replayed note)
• open-sse/executors/opencodeToolObservation.ts: covered by the request-contract suite (confirmation and threshold cases)

Reviewer Notes

• Behavior: before, every non-200 answer on reused names counted toward clearing them; after, only a 403 or 451 naming the model counts, other failures leave the streak untouched, and a 200 on reused names clears the streak without moving the stored entry.
• Merge: lands after fix(open-sse): replay title-shaped insufficient_quota refusals once #15451, then either order with fix(sse): name the egress on every opencode rotation log line #15375, fix(opencode): count silent streamed replies while the first-byte guard stays off #15455, and fix(proxies): set aside region-refused members briefly #15383; lands after fix(opencode): declare the free-tier tool fingerprint the upstream requires #15322 if that PR merges first, otherwise no rebase needed; the frozen entry for the executor moves from 1457 to 1509 with its own justification entry, keep every entry when rebasing.
• Follow-up: pause scope stays with fix(auth): pause only the refused model on the no-auth path #15443; retriable 401 stays with fix(auth): answer a paused no-auth provider with a retryable cooldown #15402; out-of-contract arming stays with fix(sse): reproduce OpenCode CLI requests and isolate model cooldowns (#14977) #15143; passing the verdict read on the replayed refusal to the notation site instead of rereading the body stays for a later change.