refactor: split emergent-patterns into focused problem-solving skills

**Restructure:**
- Split detecting-emergent-patterns (216 lines) into 5 focused skills (~60 lines each)
- Move tracing-lineages to skills/research/ (better category fit)
- Create skills/problem-solving/ category

**New problem-solving skills:**
- simplification-cascades: Find one insight that eliminates multiple components
- collision-zone-thinking: Force unrelated concepts together for breakthroughs
- meta-pattern-recognition: Spot patterns in 3+ domains
- inversion-exercise: Flip assumptions to reveal alternatives
- scale-game: Test at extremes to find fundamental limits
- when-stuck: Dispatch skill that maps stuck-symptoms to techniques

**Improvements:**
- Symptom-based when_to_use (what you'd actually think/feel)
- Quick reference tables for rapid scanning
- Pattern-based triggers (not exact phrase matching)
- Cross-references from brainstorming for discoverability

Each skill now: scannable in 30 seconds, applicable immediately, focused on one technique.

skills/collaboration/executing-plans/SKILL.md

@@ -32,9 +32,9 @@ digraph executing_modes {
 
     REVIEWING -> EXECUTING [label="Plan is sound, no concerns\n(created TodoWrite, ready to start first batch)"];
 
-    REVIEWING -> BLOCKED [label="Plan has issues that prevent starting\n(missing info, unclear instructions, dependencies)"];
+    REVIEWING -> BLOCKED [label="Plan has critical gaps\n(missing information, unclear instructions, unmet dependencies)"];
 
-    EXECUTING -> BLOCKED [label="Hit a blocker mid-batch\n(missing dependency, test fails, unclear instruction)"];
+    EXECUTING -> BLOCKED [label="Cannot proceed with current task\n(dependency missing, test failing, instruction unclear)"];
 
     EXECUTING -> REPORTING [label="Batch completed successfully\n(all tasks done, verifications pass)"];