refactor: Standardize data processing and update to Svelte 5 runes

This commit introduces a major refactoring of the data processing logic across multiple modules (events, archives, posts, sponsorships) to use a standardized pattern with . This improves consistency and maintainability.

Key changes:
- Replaced module-specific data processing with a generic helper.
- Removed deprecated  functions.
- Updated Svelte components to leverage the new Svelte 5 runes, simplifying state management.
- Fixed linting errors and updated test configurations.
- Added .

playwright.config.ts

@@ -3,10 +3,21 @@ import type { PlaywrightTestConfig } from '@playwright/test';
 const config: PlaywrightTestConfig = {
 	webServer: {
 		command: 'npm run build && npm run preview',
-		port: 4173
+		port: 4173,
+		// url: 'http://scott.localhost:5173',
+		// reuseExistingServer: true,
+		// stderr: 'pipe',
+		// stdout: 'pipe',
 	},
 	testDir: 'tests',
-	testMatch: /(.+\.)?(test|spec)\.[jt]s/
+	testMatch: /(.+\.)?(test|spec)\.[jt]s/,
+	reporter: 'list',
+	use: {
+		// Collect trace when retrying the failed test.
+		trace: 'on-first-retry',
+	},
+	// grep: /@node_modules/,
+	// grepInverse: /@node_modules/,
 };
 
 export default config;