Rename /codify to /compound and codify-docs to compound-docs

The new names better reflect the compounding engineering philosophy:
each documented solution compounds your team's knowledge.

- /codify → /compound (old command shows deprecation notice)
- codify-docs → compound-docs skill
- Updated all docs, philosophy sections, and references

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

plugins/compounding-engineering/skills/compound-docs/SKILL.md

@@ -1,5 +1,5 @@
 ---
-name: codify-docs
+name: compound-docs
 description: Capture solved problems as categorized documentation with YAML frontmatter for fast lookup
 allowed-tools:
   - Read # Parse conversation context
@@ -11,7 +11,7 @@ preconditions:
   - Solution has been verified working
 ---
 
-# codify-docs Skill
+# compound-docs Skill
 
 **Purpose:** Automatically document solved problems to build searchable institutional knowledge with category-based organization (enum-validated problem types).
 
@@ -348,7 +348,7 @@ Action:
 ## Integration Points
 
 **Invoked by:**
-- /codify command (primary interface)
+- /compound command (primary interface)
 - Manual invocation in conversation after solution confirmed
 - Can be triggered by detecting confirmation phrases like "that worked", "it's fixed", etc.