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/src/routes/briefwechsel/page.server.spec.ts

@@ -40,6 +40,7 @@ describe('korrespondenz load — no senderId', () => {
 
 		const result = await load({
 			url: makeUrl(),
+			request: new Request('http://localhost/briefwechsel'),
 			fetch: vi.fn() as unknown as typeof fetch,
 			locals: { user: readUser }
 		});
@@ -69,6 +70,7 @@ describe('korrespondenz load — senderId set, no receiverId', () => {
 
 		const result = await load({
 			url: makeUrl({ senderId: 'p1' }),
+			request: new Request('http://localhost/briefwechsel'),
 			fetch: vi.fn() as unknown as typeof fetch,
 			locals: { user: readUser }
 		});
@@ -108,6 +110,7 @@ describe('korrespondenz load — senderId and receiverId set', () => {
 
 		const result = await load({
 			url: makeUrl({ senderId: 'p1', receiverId: 'p2' }),
+			request: new Request('http://localhost/briefwechsel'),
 			fetch: vi.fn() as unknown as typeof fetch,
 			locals: { user: readUser }
 		});
@@ -137,6 +140,7 @@ describe('korrespondenz load — canWrite', () => {
 
 		const result = await load({
 			url: makeUrl({ senderId: 'p1' }),
+			request: new Request('http://localhost/briefwechsel'),
 			fetch: vi.fn() as unknown as typeof fetch,
 			locals: { user: writeUser }
 		});
@@ -160,6 +164,7 @@ describe('korrespondenz load — canWrite', () => {
 
 		const result = await load({
 			url: makeUrl({ senderId: 'p1' }),
+			request: new Request('http://localhost/briefwechsel'),
 			fetch: vi.fn() as unknown as typeof fetch,
 			locals: { user: readUser }
 		});
@@ -188,6 +193,7 @@ describe('korrespondenz load — backend error', () => {
 		await expect(
 			load({
 				url: makeUrl({ senderId: 'p1' }),
+				request: new Request('http://localhost/briefwechsel'),
 				fetch: vi.fn() as unknown as typeof fetch,
 				locals: { user: readUser }
 			})