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/components/TaskDetail.svelte

@@ -28,7 +28,6 @@
 	/** @type {() => void} */
 	export let onClose;
 
-	// Editing state — only one field at a time
 	/** @type {string|null} */
 	let editingField = null;
 
@@ -37,7 +36,6 @@
 	let editProject = '';
 	let editTagInput = '';
 
-	// Recurring instance: remember user choice for this sheet session
 	/** @type {'instance'|'template'|null} */
 	let recurringChoice = null;
 
@@ -67,17 +65,12 @@
 		0: 3
 	});
 
-	/**
-	 * Format a unix timestamp as yyyy-MM-dd for date input
-	 * @param {number} ts
-	 * @returns {string}
-	 */
+	/** @param {number} ts @returns {string} */
 	function tsToDateValue(ts) {
 		return format(fromUnix(ts), 'yyyy-MM-dd');
 	}
 
 	/**
-	 * Check if a field edit on a recurring instance needs the instance/template prompt
 	 * @param {string} field
 	 * @returns {boolean}
 	 */
@@ -124,14 +117,10 @@
 
 	function saveCurrentEdit() {
 		if (!editingField) return;
-		// Each field handles its own save via its input events
 		editingField = null;
 	}
 
-	/**
-	 * Get the UUID to update based on recurring choice
-	 * @returns {string}
-	 */
+	/** @returns {string} */
 	function getTargetUuid() {
 		if (recurringChoice === 'template' && task.parent_uuid) {
 			return task.parent_uuid;
@@ -194,7 +183,6 @@
 	async function removeTag(tag) {
 		try {
 			await tagsAPI.remove(getTargetUuid(), tag);
-			// Optimistic: update local
 			task = { ...task, tags: task.tags.filter(t => t !== tag) };
 		} catch (error) {
 			console.error('Failed to remove tag:', error);
@@ -207,7 +195,6 @@
 		editTagInput = '';
 		try {
 			await tagsAPI.add(getTargetUuid(), tag);
-			// Optimistic: update local
 			task = { ...task, tags: [...task.tags, tag] };
 		} catch (error) {
 			console.error('Failed to add tag:', error);
@@ -259,12 +246,10 @@
 		}
 	}
 
-	// After recurring choice is made, proceed with the pending edit
 	$: if (recurringChoice && pendingEditField) {
 		const field = pendingEditField;
 		pendingEditField = null;
 		if (field === 'priority-cycle') {
-			// Direct cycle
 			const next = priorityCycle[task.priority] ?? 1;
 			onUpdate(getTargetUuid(), { priority: /** @type {import('$lib/api/types.js').TaskPriority} */ (next) });
 		} else {