revert: remove automatic skill dependency installation system

- Removed dependency installation loading state from SkillSetupWizard
- Reverted SkillRuntime dependency checking and installation methods
- Cleaned up dependency-related imports and event listeners
- Documented complete implementation in skills/todo.md for future work

The dependency installation system was causing unwanted loading states
when configuring skills. All functionality has been properly reverted
while preserving implementation details for future development.

src/components/skills/SkillSetupWizard.tsx

@@ -30,6 +30,7 @@ export default function SkillSetupWizard({
 }: SkillSetupWizardProps) {
   const [state, setState] = useState<WizardState>({ phase: "loading" });
 
+
   // Start the skill (if not running) then start the setup flow on mount
   useEffect(() => {
     let cancelled = false;
@@ -162,6 +163,7 @@ export default function SkillSetupWizard({
         </div>
       );
 
+
     case "step":
       return (
         <SetupFormRenderer

src/lib/skills/runtime.ts

@@ -38,6 +38,7 @@ export class SkillRuntime {
     this.transport.onReverseRpc(handler);
   }
 
+
   /**
    * Spawn the skill subprocess.
    * Uses absolute cwd from the backend so the sidecar finds the skills package.