feat(core): sync framework security hardening and accessibility improvements

- add util.Go with panic recovery for background goroutines
- add util.EscapeLike and explicit ESCAPE clause for SQL LIKE queries
- add DummyCheckPassword and subtle.ConstantTimeCompare against timing attacks
- enforce session ID rotation upon login/oauth callback to prevent session fixation
- add sliding window login failure rate limiting and oauth state rate limiting
- fix redis client capture race in pubsub listeners and wait on stop channel
- adjust global --primary to oklch(51.1% 0.262 276.966) for WCAG AA contrast
- fix semantic heading levels and missing aria-labels across UI components
- document security, concurrency, and a11y standards in AGENTS.md

frontend/app/(main)/admin/tasks/components/task-manager.tsx

@@ -372,9 +372,9 @@ export function TaskManager() {
                     <div className='space-y-2'>
                       <div className='flex items-start justify-between'>
                         <div className='space-y-1'>
-                          <h3 className='font-semibold text-base tracking-tight'>
+                          <p className='font-semibold text-base tracking-tight'>
                             {task.name}
-                          </h3>
+                          </p>
                           <p className='text-xs text-muted-foreground leading-relaxed line-clamp-2 min-h-[36px]'>
                             {task.description}
                           </p>