refactor(commands): replace SlashCommand with Skill tool invocation

Update all workflow command files to use Skill tool instead of SlashCommand:
- Change allowed-tools: SlashCommand(*) → Skill(*)
- Convert SlashCommand(command="/path", args="...") → Skill(skill="path", args="...")
- Update descriptive text references from SlashCommand to Skill
- Remove javascript language tags from code blocks (25 files)

Affected 25 command files across:
- workflow: plan, execute, init, lite-plan, lite-fix, etc.
- workflow/test: test-fix-gen, test-cycle-execute, tdd-plan, tdd-verify
- workflow/review: review-cycle-fix, review-module-cycle, review-session-cycle
- workflow/ui-design: codify-style, explore-auto, imitate-auto
- workflow/brainstorm: brainstorm-with-file, auto-parallel
- issue: discover, discover-by-prompt, plan
- ccw, ccw-debug

This aligns with the actual Skill tool interface which uses 'skill' and 'args' parameters.

.claude/commands/workflow/review-cycle-fix.md

@@ -2,7 +2,7 @@
 name: review-cycle-fix
 description: Automated fixing of code review findings with AI-powered planning and coordinated execution. Uses intelligent grouping, multi-stage timeline coordination, and test-driven verification.
 argument-hint: "<export-file|review-dir> [--resume] [--max-iterations=N]"
-allowed-tools: SlashCommand(*), TodoWrite(*), Read(*), Bash(*), Task(*), Edit(*), Write(*)
+allowed-tools: Skill(*), TodoWrite(*), Read(*), Bash(*), Task(*), Edit(*), Write(*)
 ---
 
 # Workflow Review-Cycle-Fix Command