refactor: clean up opal-web duplication, dead code, and comment noise

- Deduplicate API_BASE (was defined in both client.js and endpoints.js)
- Extract EMPTY_STATE and persist() helper in auth store (DRY)
- Extract updateByUuid() in tasks store, normalize to .map() pattern
- Remove unused getQueueSize(), Select.svelte, and lib/index.js
- Modernize uuid.js to prefer crypto.randomUUID()
- Strip ~60 redundant comments that restated self-evident code

No behavior changes. Build passes, pre-existing type errors unchanged.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

opal-web/src/lib/api/client.js

@@ -6,7 +6,7 @@ import { get } from 'svelte/store';
  * @typedef {import('./types.js').AuthTokens} AuthTokens
  */
 
-const API_BASE = import.meta.env.VITE_API_URL || 'http://localhost:8080';
+export const API_BASE = import.meta.env.VITE_API_URL || 'http://localhost:8080';
 
 /**
  * Make authenticated API request
@@ -23,7 +23,6 @@ export async function apiRequest(endpoint, options = {}) {
 		...options.headers
 	};
 	
-	// Add auth token if available
 	if (auth.accessToken) {
 		headers['Authorization'] = `Bearer ${auth.accessToken}`;
 	}
@@ -34,11 +33,9 @@ export async function apiRequest(endpoint, options = {}) {
 			headers
 		});
 		
-		// Token expired - try refresh
 		if (response.status === 401 && auth.refreshToken) {
 			const refreshed = await refreshAccessToken(auth.refreshToken);
 			if (refreshed) {
-				// Retry with new token
 				headers['Authorization'] = `Bearer ${refreshed.access_token}`;
 				return apiRequest(endpoint, { ...options, headers });
 			}
@@ -78,7 +75,6 @@ async function refreshAccessToken(refreshToken) {
 		
 		const result = await response.json();
 		if (result.success) {
-			// Update auth store
 			authStore.setTokens(result.data);
 			return result.data;
 		}