feat(render): full-screen render page, one-active-render limit, app-wide progress

Concurrent-render ceiling (a user runs 1 render at a time unless granted more):
- Identity: TokenService emits max_renders claim from User.ParallelRenderingCeiling
- Identity: admin POST /v1/users/{id}/render-slots (AdminService.SetRenderSlotsAsync,
  clamped 1..50) — gamification or admin raises a user's ceiling
- render-svc: middleware reads max_renders (default 1); CreateJob rejects with 409
  active_render_limit when active jobs >= ceiling
- render-svc: db.CountActiveJobs + ListActiveJobs; GET /v1/renders/active returns
  in-flight renders + can_start_new

Full-screen render page (replaces the modal):
- /studio/render/[projectId]: config (resolution/fps) → live preview + progress →
  download; resumes this project's in-flight render on mount; blocks when another
  render is active; reads ?preset=
- StudioTopBar export menu now navigates to the page; RenderModal deleted (dead)

App-wide minimal progress:
- GlobalRenderProgress pill mounted in the locale layout for authed users; polls
  /api/render/active every 4s, shows thumbnail + step + % on every page, click →
  the render page; hidden on the render page and when idle

Admin: UserActions gains a "concurrent render slots" control.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/components/admin/UserActions.tsx

@@ -19,6 +19,7 @@ export function UserActions({ row }: { row: Record<string, unknown>; reload?: ()
   const [pw, setPw] = useState("");
   const [seconds, setSeconds] = useState(""); const [renders, setRenders] = useState("");
   const [planDays, setPlanDays] = useState("");
+  const [slots, setSlots] = useState(String(row.parallel_rendering_ceiling ?? "1"));
   const [tags, setTags] = useState(""); const [note, setNote] = useState(""); const [status, setStatus] = useState("new");
   // discount / affiliate
   const [dcCode, setDcCode] = useState(""); const [dcKind, setDcKind] = useState("Percentage");
@@ -114,6 +115,15 @@ export function UserActions({ row }: { row: Record<string, unknown>; reload?: ()
                 </div>
               </div>
 
+              <div className={`${card} p-3`}>
+                <label className={lbl}>تعداد رندر هم‌زمان مجاز</label>
+                <p className="mb-1.5 text-[11px] text-gray-500">پیش‌فرض ۱. با افزایش این مقدار، کاربر می‌تواند چند رندر هم‌زمان اجرا کند (پس از تازه‌سازی توکن اعمال می‌شود).</p>
+                <div className="flex gap-2">
+                  <input className={`${inp} max-w-[120px]`} type="number" min={1} max={50} value={slots} onChange={(e) => setSlots(e.target.value)} />
+                  <button className={btn} disabled={busy || !slots} onClick={() => call(`users/${id}/render-slots`, { ceiling: Number(slots) || 1 }, "ظرفیت رندر هم‌زمان به‌روزرسانی شد ✓")}>اعمال</button>
+                </div>
+              </div>
+
               <div className={`${card} flex items-center justify-between p-3`}>
                 <span className="text-sm text-gray-300">دسترسی مدیر (مدراتور)</span>
                 <div className="flex gap-2">