feat: security triage applies full label taxonomy (#766)

* feat: security triage now applies full label taxonomy

Triage mode now applies:
- Safety label (safe-to-work / malicious / needs-human-review)
- Content-type label (bug, enhancement, security, question, etc.)
- Lifecycle label (Pending Review) so downstream teams can pick up

Team-building mode now transitions lifecycle labels:
- Adds "In Progress" at start, removes it on close

Added a "Available Labels Reference" section to the triage prompt
documenting all label categories for the agent.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* feat: all security-filed issues get safe-to-work + Pending Review

Issues filed by the security team (scan findings, drift/anomaly
reports, follow-up issues from closed PRs) now automatically get
`safe-to-work` and `Pending Review` labels so downstream teams
can immediately pick them up without waiting for another triage.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: remove Pending Review from safe-to-work issues

safe-to-work already means triage is complete — adding Pending Review
is redundant and confusing. Now only UNCLEAR issues get Pending Review
(they still need human attention). SAFE issues and security-filed
issues skip straight to actionable with just safe-to-work.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* refactor: normalize all labels to kebab-case

Renamed on GitHub:
- "In Progress" → "in-progress"
- "Pending Review" → "pending-review"
- "Under Review" → "under-review"
- "good first issue" → "good-first-issue"
- "help wanted" → "help-wanted"

Updated all references in security.sh and refactor.sh to match.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* fix: align issue templates and workflows with actual repo labels

Created missing labels: cloud-request, agent-request, cli.
Replaced nonexistent needs-triage with pending-review in all templates.

Templates updated:
- bug_report: bug + pending-review
- cli_feature_request: cli + enhancement + pending-review
- cloud_request: cloud-request + enhancement + pending-review
- agent_request: agent-request + enhancement + pending-review

Workflows updated:
- refactor.yml: trigger on safe-to-work AND (bug|cli|enhancement|maintenance)
- discovery.yml: already correct (safe-to-work AND cloud-request|agent-request)
- security.yml: already correct (team-building label check)

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Sprite <noreply@sprites.dev>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.github/ISSUE_TEMPLATE/agent_request.yml

@@ -1,7 +1,7 @@
 name: Agent Request
 description: Request support for a new AI coding agent
 title: "[Agent]: "
-labels: ["agent-request", "needs-triage"]
+labels: ["agent-request", "enhancement", "pending-review"]
 body:
   - type: markdown
     attributes: