fix: resolve all 15 svelte-check type errors

- Type headers as Record<string, string> in apiRequest (client.js)
- Annotate SyncResult on result object, cast catch vars to any (sync.js)
- Widen sync.push param to Partial<Task>[] (endpoints.js)
- Fix parse() return type to reflect {task?: Task} shape (endpoints.js)
- Narrow add() param from Partial<Task> to Task (tasks.js)
- Cast parseAndCreate result to Task (tasks.js)
- Type tasksByProject grouped object as Record<string, Task[]> (tasks.js)

svelte-check now reports 0 errors and 0 warnings.

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

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

@@ -18,9 +18,10 @@ export const API_BASE = import.meta.env.VITE_API_URL || 'http://localhost:8080';
 export async function apiRequest(endpoint, options = {}) {
 	const auth = get(authStore);
 	
+	/** @type {Record<string, string>} */
 	const headers = {
 		'Content-Type': 'application/json',
-		...options.headers
+		.../** @type {Record<string, string>} */ (options.headers)
 	};
 	
 	if (auth.accessToken) {

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

@@ -76,7 +76,7 @@ export const tasks = {
 
 	/**
 	 * @param {string} input - Raw opal CLI syntax
-	 * @returns {Promise<Task>}
+	 * @returns {Promise<{task?: Task} & Task>}
 	 */
 	async parse(input) {
 		return apiRequest('/tasks/parse', {
@@ -143,7 +143,7 @@ export const sync = {
 	},
 	
 	/**
-	 * @param {Task[]} tasks
+	 * @param {Partial<Task>[]} tasks
 	 * @param {string} clientId
 	 * @returns {Promise<{processed: number, conflicts: number}>}
 	 */

opal-web/src/lib/stores/sync.js

@@ -56,7 +56,8 @@ function createSyncStore() {
 				const state = loadSyncState();
 				const queue = getQueue();
 
-				let result = {
+				/** @type {SyncResult} */
+				const result = {
 					pulled: 0,
 					pushed: 0,
 					conflicts_resolved: 0,
@@ -70,7 +71,7 @@ function createSyncStore() {
 						await syncAPI.push(tasks, state.clientId);
 						clearQueue();
 						result.pushed = queue.length;
-					} catch (error) {
+					} catch (/** @type {any} */ error) {
 						result.errors.push(`Failed to push queue: ${error.message}`);
 					}
 				}
@@ -79,7 +80,7 @@ function createSyncStore() {
 					const changes = await syncAPI.getChanges(state.lastSync, state.clientId);
 					result.pulled = changes.length;
 					// TODO: Apply changes to local state
-				} catch (error) {
+				} catch (/** @type {any} */ error) {
 					result.errors.push(`Failed to pull changes: ${error.message}`);
 				}
 
@@ -95,7 +96,7 @@ function createSyncStore() {
 				}));
 
 				return result;
-			} catch (error) {
+			} catch (/** @type {any} */ error) {
 				update(state => ({
 					...state,
 					status: 'error',

opal-web/src/lib/stores/tasks.js

@@ -42,7 +42,7 @@ function createTasksStore() {
 		async parseAndCreate(input) {
 			try {
 				const result = await tasksAPI.parse(input);
-				const created = result.task ?? result;
+				const created = /** @type {Task} */ (result.task ?? result);
 				update(tasks => [created, ...tasks]);
 				return created;
 			} catch (error) {
@@ -64,7 +64,7 @@ function createTasksStore() {
 
 		/**
 		 * Optimistic create — queues offline on failure.
-		 * @param {Partial<Task>} task
+		 * @param {Task} task
 		 */
 		async add(task) {
 			try {
@@ -172,6 +172,7 @@ export const completedTasks = derived(
 export const tasksByProject = derived(
 	tasksStore,
 	$tasks => {
+		/** @type {Record<string, Task[]>} */
 		const grouped = {};
 		$tasks.forEach(task => {
 			const project = task.project || 'No Project';