[instructions] Sync instruction files with release v0.87.0

[github-actions]

Summary: Periodic instructions-janitor sync of .github/aw/*.md against the codebase at v0.87.0 to HEAD (53175a1).

Release/change audit: only .github/aw/engines.json and .github/aw/syntax-engine.md changed in that window (DeepSeek Harness engine addition), and both were already committed in sync -- no drift there. Ran the size, duplication, and accuracy audits anyway per the edge-case rules for this task.

Accuracy fixes (code vs. docs):

• syntax-engine.md: the bare: field doc claimed codex/gemini support bare mode (--no-system-prompt / GEMINI_SYSTEM_MD=/dev/null). Neither engine sets BareMode: true in code (pkg/workflow/codex_engine.go, gemini_engine.go), and validateBareModeSupport in agent_validation.go explicitly warns bare mode is copilot/claude only. Corrected the doc and added a mention of the crush, aider, goose, and custom (GenAIScript) import-based engines from engines.json, which were not listed alongside opencode/cursor/kiro/deepseek-harness.
• safe-outputs-automation.md / syntax-agentic.md: approve-workflow-run (ApproveWorkflowRunConfig in pkg/workflow/approve_workflow_run.go) had no documentation anywhere under .github/aw/. Added a full entry plus a mention in the safe-outputs type list.
• syntax-agentic.md: added ambient-folders and threat-detection-suppress, both top-level fields in pkg/parser/schemas/main_workflow_schema.json with no prior mention in any instruction file.

Duplication reduced:

• github-agentic-workflows.md and create-agentic-workflow.md each restated a trigger-selection quick-reference table; both now point to the single canonical Decision Matrix in triggers.md.
• github-agentic-workflows.md and update-agentic-workflow.md each restated the frontmatter-vs-body recompilation rule; both now point to workflow-editing.md as the single source of truth.
• Left the ~3-line Final Steps overlap between the creator/updater prompts as-is (too small to be worth the churn).

Not changed (out of scope for this task):

• docs/src/content/docs/reference/frontmatter-full.md has the same bare-mode inaccuracy that syntax-engine.md had. This task is scoped to .github/aw/*.md; flagging here for a separate docs-focused pass.

Before/after line counts (all under their target limits):

• syntax-engine.md: 90 -> 91 (limit 400)
• syntax-agentic.md: 366 -> 375 (limit 400)
• safe-outputs-automation.md: 288 -> 301 (limit 400)
• github-agentic-workflows.md: 172 -> 160 (limit 200)
• create-agentic-workflow.md: 378 -> 368 (limit 400)
• update-agentic-workflow.md: 122 -> 119 (limit 400)

Documentation commits reviewed: compared v0.87.0 (10fb863) to HEAD (53175a1) on main: 19 commits, only .github/aw/engines.json + .github/aw/syntax-engine.md touched under docs/.github/aw (both already in sync).

Test plan:

• wc -l .github/aw/*.md confirms all edited files remain under their size targets
• Verified approve-workflow-run, ambient-folders, threat-detection-suppress, bare-mode support, and the experimental engine list against the current Go source and JSON schema
• No compiler/build changes were made -- nothing to run beyond doc review

Generated by 🧹 Instructions Janitor · sonnet50 · 416.5 AIC · ⌖ 7.83 AIC · ⊞ 6K · ◷

• expires on Aug 18, 2026, 12:59 AM UTC-08:00

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Generated by 👨‍🍳 PR Sous Chef · gpt54 · 11.6 AIC · ⌖ 7.45 AIC · ⊞ 6.3K · ◷
_{Comment /souschef to run again}

[gh-aw-bot]

@copilot quick triage for this PR:

• Please refresh the branch if needed.
• Please run the pr-finisher skill and report any remaining blockers.

Run: https://github.com/github/gh-aw/actions/runs/31939955708

Generated by 👨‍🍳 PR Sous Chef · gpt54 · 11.6 AIC · ⌖ 7.45 AIC · ⊞ 6.3K · ◷
_{Comment /souschef to run again}

[Copilot]

@copilot quick triage for this PR:

• Please refresh the branch if needed....

Ran pr-finisher triage.

• Branch is current with origin/main (609d02f contains 53175a1); no refresh needed.
• No unresolved review threads found.
• Local validation passed for make agent-report-progress-no-test, make recompile, and final make agent-report-progress.
• Full make test was run and fails on a pre-existing origin/main failure: pkg/workflow TestFormal_TestIDFormatWellFormed expects T-CTR-025 but current base maps CTR-025 to T-CTR-039.
• Prior PR/Sous Chef CI was inspected: the Sous Chef run failed in safe_outputs processing; branch moderation/command runs show action_required with no failed jobs in logs. The active Copilot run was still in progress when checked.

Remaining blockers: human CI re-trigger/approval, plus the pre-existing full make test failure if this PR requires full-suite green.

[github-actions]

🎉 This pull request is included in a new release.

Release: v0.87.1