refactor(ui): name the two regime jobs for what they actually do

"Market Regime" and "Regime Monitor" sat next to each other in Admin -> Jobs
(pipeline steps 4 and 5) reading as the same job. They are unrelated, and the
names had it backwards: "Market Regime" is the SPY 50/200 guard that drives the
TopBar trend dot and the counter-trend warning on setups, so it changes what a
setup shows; "Regime Monitor" is the observational AI/Tech thermometer that
explicitly feeds no trades. The more consequential job had the vaguer name.

  market_regime   "Market Regime"   -> "Market Trend (SPY)"
  regime_monitor  "Regime Monitor"  -> "AI/Tech Risk Monitor"

Display strings only. The job *ids* are persisted -- they key the pipeline step
list, cron config, runtime tracking and run history -- so they are untouched,
as is the /regime route, which keeps existing links working.

The label the admin UI renders comes from JOB_LABELS in admin_service (via
routers/jobs.py), not from the scheduler's APScheduler `name=`. Both are updated;
only the former is user-visible.

Carries the vocabulary through the rest of the surface so it does not half-land:
page title, nav ("Regime" -> "Risk"), the empty-state instruction that names the
job to run, the quadrant alert toggle, the morning-pipeline hint, and the
Telegram alert headline ("Regime quadrant change" -> "AI/Tech risk quadrant
change"). No test asserts any of these strings.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

frontend/src/components/layout/MobileNav.tsx

@@ -7,7 +7,7 @@ const navItems = [
   { to: '/', label: 'Overview', end: true },
   { to: '/market', label: 'Market', end: false },
   { to: '/signals', label: 'Signals', end: false },
-  { to: '/regime', label: 'Regime', end: false },
+  { to: '/regime', label: 'Risk', end: false },
 ];
 
 export default function MobileNav() {

frontend/src/components/layout/TopBar.tsx

@@ -13,7 +13,8 @@ const navItems = [
   { to: '/', label: 'Overview', end: true },
   { to: '/market', label: 'Market', end: false },
   { to: '/signals', label: 'Signals', end: false },
-  { to: '/regime', label: 'Regime', end: false },
+  // Route stays /regime so existing links keep working; only the label changes.
+  { to: '/regime', label: 'Risk', end: false },
 ];
 
 const linkClasses = (isActive: boolean) =>