chore: regenerate all SKILL.md files

Regenerated from templates after Confusion Protocol, GBrain resolver
placeholders, slop:diff in review, HARD GATE reminders, investigation
learnings, design doc visibility, and retro non-git context changes.

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

investigate/SKILL.md

@@ -392,6 +392,19 @@ AI makes completeness near-free. Always recommend the complete option over short
 
 Include `Completeness: X/10` for each option (10=all edge cases, 7=happy path, 3=shortcut).
 
+## Confusion Protocol
+
+When you encounter high-stakes ambiguity during coding:
+- Two plausible architectures or data models for the same requirement
+- A request that contradicts existing patterns and you're unsure which to follow
+- A destructive operation where the scope is unclear
+- Missing context that would change your approach significantly
+
+STOP. Name the ambiguity in one sentence. Present 2-3 options with tradeoffs.
+Ask the user. Do not guess on architectural or data model decisions.
+
+This does NOT apply to routine coding, small features, or obvious changes.
+
 ## Completion Status Protocol
 
 When completing a skill workflow, report status using one of:
@@ -559,6 +572,8 @@ Fixing symptoms creates whack-a-mole debugging. Every fix that doesn't address r
 
 ---
 
+
+
 ## Phase 1: Root Cause Investigation
 
 Gather context before forming any hypothesis.
@@ -575,6 +590,8 @@ Gather context before forming any hypothesis.
 
 4. **Reproduce:** Can you trigger the bug deterministically? If not, gather more evidence before proceeding.
 
+5. **Check investigation history:** Search prior learnings for investigations on the same files. Recurring bugs in the same area are an architectural smell. If prior investigations exist, note patterns and check if the root cause was structural.
+
 ## Prior Learnings
 
 Search for relevant learnings from previous sessions:
@@ -736,6 +753,12 @@ Status:          DONE | DONE_WITH_CONCERNS | BLOCKED
 ════════════════════════════════════════
 ```
 
+Log the investigation as a learning for future sessions. Use `type: "investigation"` and include the affected files so future investigations on the same area can find this:
+
+```bash
+~/.claude/skills/gstack/bin/gstack-learnings-log '{"skill":"investigate","type":"investigation","key":"ROOT_CAUSE_KEY","insight":"ROOT_CAUSE_SUMMARY","confidence":9,"source":"observed","files":["affected/file1.ts","affected/file2.ts"]}'
+```
+
 ## Capture Learnings
 
 If you discovered a non-obvious pattern, pitfall, or architectural insight during
@@ -761,6 +784,8 @@ staleness detection: if those files are later deleted, the learning can be flagg
 **Only log genuine discoveries.** Don't log obvious things. Don't log things the user
 already knows. A good test: would this insight save time in a future session? If yes, log it.
 
+
+
 ---
 
 ## Important Rules