fix: Resolve test issues and update tasks

- Fix a11y issues in modal backdrops (keyboard handler + ARIA role)
- Increase build verification test timeouts
- Update tasks.md with current test status (157/157 passing)
- Document resolved issues #22, #23, #24

frontend/tests/unit/build-verification.spec.ts

@@ -10,9 +10,15 @@ import * as path from 'path';
  * Note: There is 1 known TypeScript warning in DataTable.svelte (generics syntax)
  * that does not affect runtime behavior.
  * 
+ * Note: These tests may trigger a vitest worker timeout warning, but all tests pass.
+ * This is a known vitest infrastructure issue with long-running tests.
+ * 
  * Run with: npm run test:unit -- tests/unit/build-verification.spec.ts
  */
 
+// Increase vitest timeout for these long-running tests
+const BUILD_TIMEOUT = 360000; // 6 minutes
+
 describe('Build Verification', () => {
 	it('should complete TypeScript check', async () => {
 		let output: string;
@@ -20,7 +26,7 @@ describe('Build Verification', () => {
 		try {
 			output = execSync('npm run check', {
 				encoding: 'utf-8',
-				timeout: 120000,
+				timeout: BUILD_TIMEOUT,
 				stdio: ['pipe', 'pipe', 'pipe']
 			});
 		} catch (error: any) {
@@ -41,9 +47,9 @@ describe('Build Verification', () => {
 		const criticalErrorMatch = output.match(/svelte-check found (\d+) error/i);
 		const errorCount = criticalErrorMatch ? parseInt(criticalErrorMatch[1], 10) : 0;
 		
-		// We expect 1 known error in DataTable.svelte
-		expect(errorCount, `Expected 1 known error (DataTable generics), found ${errorCount}`).toBeLessThanOrEqual(1);
-	}, 180000); // 3 minute timeout
+		// We expect 0-1 known error in DataTable.svelte
+		expect(errorCount, `Expected 0-1 known error (DataTable generics), found ${errorCount}`).toBeLessThanOrEqual(1);
+	}, BUILD_TIMEOUT);
 
 	it('should complete production build successfully', async () => {
 		let output: string;
@@ -52,7 +58,7 @@ describe('Build Verification', () => {
 		try {
 			output = execSync('npm run build', {
 				encoding: 'utf-8',
-				timeout: 300000, // 5 minutes
+				timeout: BUILD_TIMEOUT,
 				stdio: ['pipe', 'pipe', 'pipe']
 			});
 		} catch (error: any) {
@@ -77,7 +83,7 @@ describe('Build Verification', () => {
 			output,
 			'Build should indicate successful completion'
 		).toMatch(/✓ built|✔ done|built in \d+/i);
-	}, 300000); // 5 minute timeout
+	}, BUILD_TIMEOUT);
 
 	it('should produce expected build artifacts', () => {
 		const outputDir = path.join(process.cwd(), '.svelte-kit', 'output');