fix(tests): add missing Sentry mock event fields across 14 spec files; fix test:coverage semicolon

`@sentry/sveltekit` wraps load functions and reads `event.request.method` and
`event.url.pathname`. Mock events that omitted `request` or `url` threw
`TypeError: Cannot read properties of undefined` on every invocation, silently
masking 86 test failures on main.

Two root causes fixed:
- Added `request: new Request(...)` (and `url: new URL(...)` where absent) to
  all mock event objects in 14 `*.server.spec.ts` files
- Changed `;` to `&&` in the `test:coverage` npm script so a failing server
  run propagates its exit code instead of being swallowed by the client run

All 576 server-project tests now pass.

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

frontend/package.json

@@ -16,7 +16,7 @@
 		"lint:boundary-demo": "eslint src/lib/tag/__fixtures__/",
 		"test:unit": "vitest",
 		"test": "npm run test:unit -- --run",
-		"test:coverage": "vitest run --coverage --project=server; vitest run -c vitest.client-coverage.config.ts --coverage",
+		"test:coverage": "vitest run --coverage --project=server && vitest run -c vitest.client-coverage.config.ts --coverage",
 		"test:e2e": "playwright test",
 		"test:e2e:headed": "playwright test --headed",
 		"test:e2e:ui": "playwright test --ui",