Hide all wallet entry points from non-B2B users

[leoxk]

What changed

• hide the Wallet link in the mobile account drawer unless the current user is in the approved b2b group
• hide the Wallet call-to-action in dashboard balance summary cards for non-B2B users
• remove the Add credits onboarding step from the dashboard for non-B2B users
• reuse the same wallet visibility policy already used by the sidebar and profile dropdown

Why

The previous B2B wallet change protected the API and main navigation, but static acceptance review found remaining mobile and dashboard links. Those links ultimately reached a protected 403 page, so payment security was intact, but the approval-only customer experience was incomplete.

Safety

• backend wallet and payment authorization remains unchanged
• approved b2b users retain every Wallet entry point
• non-B2B users keep their balance and usage dashboard; only payment navigation is removed
• existing users, groups, quotas, channels, models, and payment credentials are unchanged

Validation

• git diff --check
• frontend typecheck, production build, and Glimo policy audit will run in CI because Bun is not installed on this Mac