feat: implement Story 2.2 — Priority Alerts Panel with UI fixes

Add PriorityAlertsPanel component to the dashboard, update DashboardController
with alert logic, and apply misc UI fixes across sidebar, forms, and pages.
Includes epic-1 retrospective and sprint status update.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

package.json

@@ -33,6 +33,7 @@
     },
     "dependencies": {
         "@inertiajs/vue3": "^2.3.7",
+        "@tanstack/vue-table": "^8.21.3",
         "@vueuse/core": "^12.8.2",
         "class-variance-authority": "^0.7.1",
         "clsx": "^2.1.1",