Orphaned truth-gate fixture left behind by #1431

[groupthinking]

Problem

ci: retire the agent-completion truth gate (#1431) (8cd4a10ca) deleted both consumers of tests/fixtures/agent_completion/pr_813.json:

• scripts/ci/agent_completion_gate.py — deleted
• tests/unit/test_agent_completion_gate.py — deleted

The fixture itself was not deleted, so tests/fixtures/agent_completion/ remains on main with no reader.

Evidence

$ git ls-tree -r --name-only origin/main | grep -E 'agent_completion_gate|agent-completion-enforcement'
(no output — both deleted)

$ grep -rn "agent_completion" --include=*.py --include=*.yml --include=*.yaml \
    --include=*.md --include=*.json --include=*.sh . | grep -v '^./tests/fixtures/agent_completion/'
./docs/runbook/pr-remediation-report-2026-08-04.md:11:> `agent-completion-enforcement.yml`, `agent_completion_gate.py`, and

The single remaining hit is a historical runbook narrating the retirement. It is prose about the deletion, not a load of the fixture, and should stay as written.

Why it matters

The fixture encodes the retired gate's payload schema (policy.applicable, agent_login, run_id, head_sha). Left in the tree it reads as a live contract for a mechanism that no longer exists — the same class of misleading-artifact problem #1431 and #1434 were closing.

Acceptance criteria

• tests/fixtures/agent_completion/ is removed from the tree.
• No test collection error or new failure results — verified by running the suites that reference tests/fixtures/.
• The historical runbook reference in docs/runbook/pr-remediation-report-2026-08-04.md is left unchanged.

Scope

Deletion only. This issue does not reopen the truth-gate decision, which #1431 settled.

[linear-code]

GRV-379

[coderabbitai]

🔗 Related PRs

#277 - Vercel remediation complete: waitUntil adoption + active middleware + @vercel/functions package (resolves three user-defined outcomes; 16-agent verification-gate consolidated PASS on full matrix) [closed]
#404 - fix(web): sync package-lock with @vercel/functions (unblocks #277 auto-merge) [merged]
#693 - fix(ci): unblock the entire PR backlog — resolve invalid agent_network.json + restore apps/web type-check script [merged]
#872 - ci: enforce deterministic agent completion truth gate [merged]

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