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/test-cycle-execute.md

@@ -2,7 +2,7 @@
 name: test-cycle-execute
 description: Execute test-fix workflow with dynamic task generation and iterative fix cycles until test pass rate >= 95% or max iterations reached. Uses @cli-planning-agent for failure analysis and task generation.
 argument-hint: "[--resume-session=\"session-id\"] [--max-iterations=N]"
-allowed-tools: SlashCommand(*), TodoWrite(*), Read(*), Bash(*), Task(*)
+allowed-tools: Skill(*), TodoWrite(*), Read(*), Bash(*), Task(*)
 ---
 
 # Workflow Test-Cycle-Execute Command