[aw-maintenance:failures-investigator] Fix: Daily Runtime Threat Scan agent job fails at "Execute GitHub Copilot CLI" (needs full log evidence)

**Target repository**: `github/gh-aw-actions`
**Affected workflow**: `.github/workflows/daily-runtime-threat-scan.lock.yml` ("Daily Runtime Threat Scan")

### Problem
The `agent` job fails at the "Execute GitHub Copilot CLI" step in 2 of the last 3 runs. Both truncated (50-line) log tails show identical successful setup up to MCP Gateway startup, then cut off before any explicit error line is printed.

### Affected runs
- `github/gh-aw-actions` run 33717072313: https://github.com/github/gh-aw-actions/actions/runs/33717072313 (2026-09-03T04:59:45Z)
- `github/gh-aw-actions` run 33684447255: https://github.com/github/gh-aw-actions/actions/runs/33684447255 (2026-09-02T21:18:57Z)

### Probable root cause (needs more evidence)
Both runs show: MCP servers `github` and `safeoutputs` connect successfully, "All checks passed", MCP Gateway starts in containerized mode, and baked-in WASM guards are auto-detected at `/guards`. The available log window ends immediately after `[INFO] Auto-detected baked-in WASM guards at /guards`, before any error is surfaced. This is consistent with a failure during or after WASM guard initialization (e.g., a guard blocking a required network/tool call, or a crash in the containerized gateway), but the exact failing statement could not be confirmed — full job log retrieval was blocked by a GitHub API rate limit during this investigation (retry after 6m34s).

### Proposed remediation
1. Fetch the complete (non-truncated) `agent` job log for run 33717072313 or 33684447255 to find the first `##[error]` or non-zero exit code after the WASM guard detection line.
2. If the failure is guard-related, review the WASM guard configuration referenced by `daily-runtime-threat-scan.lock.yml` (network/firewall rules) for a rule that unexpectedly blocks a call the Copilot CLI needs to make.
3. If it is a gateway crash, check for a version mismatch or resource limit in the containerized MCP gateway setup.

### Success criteria
- Root cause identified from full logs and documented.
- "Daily Runtime Threat Scan" completes the "Execute GitHub Copilot CLI" step successfully on the next 2 consecutive scheduled runs.

See the failure report issue for full context (aw-maintenance:failures-investigator, `github/gh-aw-actions`, 24h window).

### Control Plane
- Correlation ID: 33804008600-65
- Central repository: githubnext/gh-aw-cao
- Control plane run: https://github.com/githubnext/gh-aw-cao/actions/runs/33804008600

> Generated by [:rotating_light: AW Maintenance / Failures](https://github.com/githubnext/gh-aw-cao/actions/runs/33804008600) · copilot · auto · 43.5 AIC · ⌖ 15.6 AIC · ⊞ 14.9K · [◷](https://github.com/search?q=repo%3Agithubnext%2Fgh-aw-cao+is%3Aissue+%22gh-aw-workflow-call-id%3A+githubnext%2Fgh-aw-cao%2Faw-failures-investigator%22&type=issues)
> - [x] expires on Sep 17, 2026, 8:53 PM UTC

Start with .github/workflows/daily-runtime-threat-scan.lock.yml and fetch the complete agent job logs for runs 33717072313 and 33684447255, looking after the WASM guard detection line for the first error or non-zero exit. If the logs identify a guard rule or containerized MCP gateway issue, inspect the referenced configuration and document the root cause; done means two consecutive scheduled runs complete the Execute GitHub Copilot CLI step successfully.

Written by the indexing model from the issue text.