fix(entitlements): billing reachable in settings modal + conversion redesign (#821)

- Register BillingSettingsContent in SETTINGS_SECTIONS so the settings MODAL renders Abonnemang (it was falling back to Företag — billing was only a standalone page, never a registered section). Page is now a thin wrapper over the same component.
- Add GET /api/billing/status (isPaying / configured / trialEndsAt) so the client section gets state without server-only reads.
- Redesign for conversion: trial days-left urgency banner, reactive monthly/yearly price with a 'Spara 2 mån' badge, full-width price-bearing CTA, Stripe trust line, design-system-compliant chrome (flat Card, no shadow/rounded-xl, on-scale spacing, serif headline). Trialing companies now see the upgrade path (not the manage button).

The reported 'peach band' was not reproduced in code — no peach/salmon color exists in the app CSS and the only bottom drag-handle is in a md:hidden mobile sheet; most likely a macOS screenshot/desktop artifact.

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

app/api/billing/status/route.ts

@@ -0,0 +1,48 @@
+import { NextResponse } from 'next/server'
+import { requireAuth } from '@/lib/auth/require-auth'
+import { requireCompanyId } from '@/lib/company/context'
+import { isStripeConfigured } from '@/lib/stripe/client'
+
+/**
+ * Billing status for the client-rendered billing section (which lives inside the
+ * settings modal Dialog and can't read the DB server-side). Returns whether the
+ * company is paying, whether Stripe checkout is configured, and the trial expiry
+ * (for the days-left urgency banner). Read-only.
+ */
+export async function GET() {
+  const { user, supabase, error } = await requireAuth()
+  if (error) return error
+
+  let companyId: string | null = null
+  try {
+    companyId = await requireCompanyId(supabase, user.id)
+  } catch {
+    companyId = null
+  }
+
+  let isPaying = false
+  let trialEndsAt: string | null = null
+  if (companyId) {
+    const { data: sub } = await supabase
+      .from('company_subscriptions')
+      .select('status')
+      .eq('company_id', companyId)
+      .maybeSingle()
+    const status = (sub as { status: string | null } | null)?.status ?? null
+    // Paying = a real subscription. Deliberately excludes 'trialing' so a
+    // trialing company still sees the upgrade path (not the manage button).
+    isPaying = status === 'active' || status === 'past_due'
+
+    const { data: trial } = await supabase
+      .from('capability_grants')
+      .select('expires_at')
+      .eq('company_id', companyId)
+      .eq('source', 'trial')
+      .order('expires_at', { ascending: false })
+      .limit(1)
+      .maybeSingle()
+    trialEndsAt = (trial as { expires_at: string | null } | null)?.expires_at ?? null
+  }
+
+  return NextResponse.json({ isPaying, configured: isStripeConfigured(), trialEndsAt })
+}