Upgrade gh-aw to v0.91.5 prerelease

[pelikhan]

Summary

Upgrade repository workflows from gh-aw v0.91.4 to the latest prerelease, v0.91.5, and the local CLI from v0.91.2 to v0.91.5.

• Regenerate all 15 workflow lock files, command dispatcher, maintenance workflow, and auto-upgrade workflow.
• Update SHA-pinned gh-aw setup actions and the Copilot setup extension version; generated workflows now use digest-pinned AWF v0.28.44 images.
• Make DeepSeek Harness's existing unrestricted native Bash behavior explicit with bash: ["*"]; its previously declared command allowlist was not enforced and is now rejected by compilation. Preserve AWF confinement, read-only judges, and fixed-fixture instructions.
• Preserve Codex bash: false, generated features.shell_tool=false, existing GitHub permissions, and all pinned skills.
• Refresh directly related version and provider guidance.

Release changes

v0.91.5 adds ordered model fallback and auto routing across additional engines, routing visibility, and reliability fixes for Codex setup, safe outputs, and credential handling. Existing workflow model selections are unchanged.

Upgrade method and migration notes

Ran gh aw upgrade --pre-releases, then manually addressed the DeepSeek declaration and recompiled with strict validation. The upstream bash-allowlist-unsupported-engine-guided-error codemod incorrectly flags Codex full shell denial; the v0.91.5 compiler and upstream compiler tests explicitly support it. Kept shell denial intact and verified remaining migrations with that codemod disabled rather than widening Codex permissions. Reverted unrelated skill pin refreshes performed by the upgrade command.

The upgrade refreshed actions/upload-artifact to SHA-pinned v7.0.2 and normalized the existing GitHub Script v9 reference to v9.0.0.

Validation

• gh aw compile --strict --validate: all 15 workflows compile successfully. The only warning is the existing fixed daily 09:00 UTC schedule; its timing is intentionally unchanged.
• npm test: 664 tests passed across 23 files.
• npm run typecheck: passed.
• Checked every workflow's compiler version, unchanged job permissions, preserved skill pins, and generated Codex shell denial.
• Independently verified all four AWF image digests against the registry.
• Checked documentation links, documentation size regression signals, and git diff --check.

No live workflow executions were dispatched.