feat: add escalation protocol to preamble — all skills get DONE/BLOCKED/NEEDS_CONTEXT

Every skill now reports completion status (DONE, DONE_WITH_CONCERNS, BLOCKED,
NEEDS_CONTEXT) and has escalation rules: 3 failed attempts → STOP, security
uncertainty → STOP, scope exceeds verification → STOP.

"It is always OK to stop and say 'this is too hard for me.'"

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

retro/SKILL.md

@@ -72,6 +72,31 @@ Then run: `mkdir -p ~/.gstack/contributor-logs && open ~/.gstack/contributor-log
 
 Slug: lowercase, hyphens, max 60 chars (e.g. `browse-snapshot-ref-gap`). Skip if file already exists. Max 3 reports per session. File inline and continue — don't stop the workflow. Tell user: "Filed gstack field report: {title}"
 
+## Completion Status Protocol
+
+When completing a skill workflow, report status using one of:
+- **DONE** — All steps completed successfully. Evidence provided for each claim.
+- **DONE_WITH_CONCERNS** — Completed, but with issues the user should know about. List each concern.
+- **BLOCKED** — Cannot proceed. State what is blocking and what was tried.
+- **NEEDS_CONTEXT** — Missing information required to continue. State exactly what you need.
+
+### Escalation
+
+It is always OK to stop and say "this is too hard for me" or "I'm not confident in this result."
+
+Bad work is worse than no work. You will not be penalized for escalating.
+- If you have attempted a task 3 times without success, STOP and escalate.
+- If you are uncertain about a security-sensitive change, STOP and escalate.
+- If the scope of work exceeds what you can verify, STOP and escalate.
+
+Escalation format:
+```
+STATUS: BLOCKED | NEEDS_CONTEXT
+REASON: [1-2 sentences]
+ATTEMPTED: [what you tried]
+RECOMMENDATION: [what the user should do next]
+```
+
 # /retro — Weekly Engineering Retrospective
 
 Generates a comprehensive engineering retrospective analyzing commit history, work patterns, and code quality metrics. Team-aware: identifies the user running the command, then analyzes every contributor with per-person praise and growth opportunities. Designed for a senior IC/CTO-level builder using Claude Code as a force multiplier.