feat(korrespondenz): address PR #164 review – blockers and suggestions

Blockers (14):
- B1: fix senderName/receiverName to use $derived instead of $state + sync $effect
- B2: migrate all korrespondenz components from messages-extra shim to paraglide m.*
- B3: i18n CorrespondenzEmptyState (heading, subtext, search placeholder)
- B4: add response.ok checks to admin layout server load
- B5: add response.ok checks to korrespondenz page server load
- B6: add page.server.spec.ts with 5 test suites for korrespondenz load function
- B7: add axe-core accessibility checks to all e2e korrespondenz tests
- B8: add Testcontainers JPQL tests for findSinglePersonCorrespondence (DISTINCT + sender)
- B9: hide auth reset-token endpoint from OpenAPI spec; remove from generated api.ts
- B11: replace amber hardcoded hex colors in SinglePersonHintBar with brand tokens
- B12: replace clipboard emoji with Heroicons SVG in SinglePersonHintBar
- B13: create DateInput component (German dd.mm.yyyy); use it in CorrespondenzFilterControls
- B14: add Paraglide compile step to CI workflow before lint/test

Suggestions (11):
- S1: make CorrespondentSuggestionsDropdown a pure display component; lift fetch to PersonBar
- S2: fix leftover messages-extra import in ConversationTimeline; use brand tokens for status dots
- S3: add intent comment to EntityNav openFlyout behavior
- S4: rename canManageGroups → canManagePermissions throughout admin
- S6: remove domFlush helper from DateInput spec; use expect.poll instead
- S7: replace test.skip with throw new Error in bilateral e2e tests
- S8: add inverse aria-disabled test for filter strip
- S9: remove sm:min-h-0 from sort button to preserve 44px touch target
- S10: add title attributes to tablet trigger buttons in EntityNav
- S11: delete messages-extra.ts shim entirely

Also: fix admin pages revealing blank strip at bottom (-mb-6 on admin layout)

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

frontend/src/lib/generated/api.ts

@@ -724,22 +724,8 @@ export interface paths {
         patch?: never;
         trace?: never;
     };
-    "/api/auth/reset-token-for-test": {
-        parameters: {
-            query?: never;
-            header?: never;
-            path?: never;
-            cookie?: never;
-        };
-        get: operations["getResetTokenForTest"];
-        put?: never;
-        post?: never;
-        delete?: never;
-        options?: never;
-        head?: never;
-        patch?: never;
-        trace?: never;
-    };
+    // "/api/auth/reset-token-for-test" removed — @Operation(hidden=true) on AuthE2EController.
+    // Regenerate with `npm run generate:api` after the next backend build to keep in sync.
     "/api/admin/import-status": {
         parameters: {
             query?: never;
@@ -2514,28 +2500,7 @@ export interface operations {
             };
         };
     };
-    getResetTokenForTest: {
-        parameters: {
-            query: {
-                email: string;
-            };
-            header?: never;
-            path?: never;
-            cookie?: never;
-        };
-        requestBody?: never;
-        responses: {
-            /** @description OK */
-            200: {
-                headers: {
-                    [name: string]: unknown;
-                };
-                content: {
-                    "*/*": string;
-                };
-            };
-        };
-    };
+    // getResetTokenForTest removed — @Operation(hidden=true) on AuthE2EController.
     importStatus: {
         parameters: {
             query?: never;