[copilot-token-optimizer] Architecture Guardian: reduce 47-turn analysis via bash pre-step consolidation (#28141)

* Initial plan

* feat: optimize architecture-guardian with bash pre-step consolidation

- Add bash pre-step that collects all file metrics upfront into
  /tmp/gh-aw/agent/arch-metrics.json, replacing ~20-30 per-file
  agent turns with a single deterministic bash step
- Remove github: toolsets: [repos] (unused in local static analysis)
- Remove edit: tool (workflow is read-only, tool was never called)
- Simplify violation reporting to 2-line templated format per violation
  instead of verbose 3-part narrative suggestions
- Improve Go receiver method detection in awk pattern
- Expand JS function detection to cover arrow functions and exports
- Add comment explaining go list error handling
- Add instruction for agent to replace template placeholders

Estimated savings: ~800K-1.1M tokens per run (~40-55% reduction)
Reduces expected turns from 47 to ~15-20

Agent-Logs-Url: https://github.com/github/gh-aw/sessions/8b9b7035-c5bd-4617-9684-7537d0c6b157

Co-authored-by: lpcox <15877973+lpcox@users.noreply.github.com>

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Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: lpcox <15877973+lpcox@users.noreply.github.com>

Author: Copilot