feat(dashboard): show the user's work plan for today

Adds a "Můj plán na dnešek" card near the clock-in: for the logged-in
user it shows today's work-plan entry — category (coloured dot + label),
the project/site (the "where"), the note, and a "součást rozsahu …" badge
only for genuinely multi-day ranges. A muted "Pro dnešek nemáte
naplánováno." empty state when nothing is scheduled.

Server: GET /api/admin/dashboard now returns today_plan, reusing
plan.service resolveCell (override-beats-range precedence) for the current
user + today's local (Prague) date, enriched with the category label +
colour so the widget needs no extra query. Gated by attendance.record /
attendance.manage (the plan permission); omitted otherwise. No migration.

Verified in Chrome: renders today's entry (Práce · OBJ-2026-006 — koko)
with the category colour. tsc -b --noEmit, npm run build, vitest 152/152.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/admin/pages/Dashboard.tsx

@@ -19,6 +19,9 @@ import DashActivityFeed from "../components/dashboard/DashActivityFeed";
 import DashAttendanceToday from "../components/dashboard/DashAttendanceToday";
 import DashProfile from "../components/dashboard/DashProfile";
 import DashSessions from "../components/dashboard/DashSessions";
+import DashTodayPlan, {
+  type TodayPlan,
+} from "../components/dashboard/DashTodayPlan";
 
 const API_BASE = "/api/admin";
 
@@ -69,6 +72,7 @@ interface DashData {
   pending_orders?: number;
   unpaid_invoices?: number;
   pending_leave_requests?: number;
+  today_plan?: TodayPlan | null;
   [key: string]: unknown;
 }
 
@@ -317,6 +321,13 @@ export default function Dashboard() {
           <DashKpiCards dashData={dashData ?? null} />
         )}
 
+      {/* My work plan for today — paired with the clock-in below */}
+      {!dashLoading &&
+        (hasPermission("attendance.record") ||
+          hasPermission("attendance.manage")) && (
+          <DashTodayPlan plan={dashData?.today_plan ?? null} />
+        )}
+
       {/* Quick actions */}
       {!dashLoading && (
         <DashQuickActions