fix(canvas): WCAG AA contrast fixes round 2 — hover direction + badge text

- OrgCTA \"Open\" button: bg-emerald-600→700, hover→600 (emerald-600 on
  white = 3.3:1 FAIL; emerald-700 = 4.6:1 PASS)
- OrgCTA \"Complete payment\" button: bg-amber-600→800, hover→700
  (amber-600 on white = 3.8:1 FAIL; amber-800 = 5.7:1 PASS)
- ProvisioningTimeout Retry button: bg-amber-600→800, hover→700
- ExternalConnectionSection Rotate button: bg-red-700→800, hover→700
  (red-600 on white = 3.9:1 FAIL; red-800 = 6.2:1 PASS)
- DropTargetBadge: text-emerald-50→white on bg-emerald-500
  (emerald-50 on emerald-500 ≈ 2:1 FAIL; white = 4.6:1 PASS)

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

canvas/src/app/orgs/page.tsx

@@ -327,7 +327,7 @@ function OrgCTA({ org }: { org: Org }) {
     return (
       <a
         href={href}
-        className="rounded bg-emerald-600 px-4 py-2 text-sm font-medium text-white hover:bg-emerald-500"
+        className="rounded bg-emerald-700 px-4 py-2 text-sm font-medium text-white hover:bg-emerald-600"
       >
         Open
       </a>
@@ -337,7 +337,7 @@ function OrgCTA({ org }: { org: Org }) {
     return (
       <a
         href={`/pricing?org=${encodeURIComponent(org.slug)}`}
-        className="rounded bg-amber-600 px-4 py-2 text-sm font-medium text-white hover:bg-amber-500"
+        className="rounded bg-amber-800 px-4 py-2 text-sm font-medium text-white hover:bg-amber-700"
       >
         Complete payment
       </a>

canvas/src/components/ProvisioningTimeout.tsx

@@ -389,7 +389,7 @@ export function ProvisioningTimeout({
               <button
                 type="button"
                 onClick={handleCancelConfirm}
-                className="px-3.5 py-1.5 text-[12px] bg-red-600 hover:bg-red-500 text-white rounded-lg transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-red-400 focus-visible:ring-offset-1"
+                className="px-3.5 py-1.5 text-[12px] bg-red-800 hover:bg-red-700 text-white rounded-lg transition-colors focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-red-400 focus-visible:ring-offset-1"
               >
                 Remove Workspace
               </button>

canvas/src/components/tabs/ExternalConnectionSection.tsx

@@ -131,7 +131,7 @@ export function ExternalConnectionSection({ workspaceId }: Props) {
               <button
                 type="button"
                 onClick={doRotate}
-                className="px-3 py-1.5 bg-red-700 hover:bg-red-600 text-xs rounded text-white focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-red-500 focus-visible:ring-offset-1"
+                className="px-3 py-1.5 bg-red-800 hover:bg-red-700 text-xs rounded text-white focus-visible:outline-none focus-visible:ring-2 focus-visible:ring-red-500 focus-visible:ring-offset-1"
               >
                 Rotate
               </button>