feat: add triggers to all 38 skill templates

Multi-word, skill-specific trigger keywords for GBrain's RESOLVER.md
router. Each skill gets 3-6 triggers derived from its "Use when asked
to..." description text. Avoids single generic words that would collide
across skills (e.g., "debug this" not "debug").

These are distinct from voice-triggers (speech-to-text aliases) and
serve GBrain's checkResolvable() validation.

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

design-shotgun/SKILL.md.tmpl

@@ -9,6 +9,10 @@ description: |
   "visual brainstorm", or "I don't like how this looks".
   Proactively suggest when the user describes a UI feature but hasn't seen
   what it could look like. (gstack)
+triggers:
+  - explore design variants
+  - show me design options
+  - visual design brainstorm
 allowed-tools:
   - Bash
   - Read