fix(billing): remove unnecessary 'human-only / cancel via support' preamble (#71)

User feedback: the ROBanner at the top of /app/billing carries copy that
duplicates information the rest of the page already communicates —
- the "stay clickable" sentence is implied by the CTAs that ARE clickable
- the "cancel via support" sentence is in the FAQ + the downgrade mailto

The banner adds vertical noise above the pricing grid and pushes the
actual upgrade tiles below the fold on smaller viewports. Remove it.

If the policy ever needs an in-product explanation, surface it inline on
the specific affordance (e.g., a tooltip on a disabled cancel button)
rather than as a page-level banner.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: mastermanas805

src/pages/BillingPage.tsx

@@ -320,13 +320,6 @@ export function BillingPage() {
 
   return (
     <>
-      <ROBanner variant="write" showAsk={false}>
-        <strong>Upgrades and card updates stay clickable on this page</strong> — the
-        agent doesn't have payment credentials, so the human has to drive the
-        Razorpay flow. <strong>To cancel or downgrade, contact support</strong> —
-        we don't expose a self-serve path on purpose.
-      </ROBanner>
-
       {/* Pricing grid: 4 tiers side-by-side with Pro highlighted. Replaces
           the single-plan upgrade card. The grid owns its own frequency
           toggle (Annual default) and renders "Your plan" on the current