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/init.md

@@ -47,7 +47,7 @@ Analysis Flow:
    ├─ Display summary
    └─ Ask about guidelines configuration
        ├─ If guidelines empty → Ask user: "Configure now?" or "Skip"
-       │   ├─ Configure now → SlashCommand(/workflow:init-guidelines)
+       │   ├─ Configure now → Skill(skill="workflow:init-guidelines")
        │   └─ Skip → Show next steps
        └─ If guidelines populated → Show next steps only
 
@@ -253,7 +253,7 @@ if (!isGuidelinesPopulated) {
 
   if (userChoice.answers["Guidelines"] === "Configure now (Recommended)") {
     console.log("\n🔧 Starting guidelines configuration wizard...\n");
-    SlashCommand(command="/workflow:init-guidelines");
+    Skill(skill="workflow:init-guidelines");
   } else {
     console.log(`
 Next steps: