update from user testing payment platform

MEMORY.md

@@ -336,4 +336,6 @@
 - Note: `svelte-kit sync` needed after changing load return shapes or `$types` staleness doubles the error count.
 - **/admin login pattern:** action sets `platform_session` cookie + returns `{success:true}`; the form's `use:enhance` callback flips a local `authed` view state — no redirect, no reliance on inline invalidation or fetch-time Set-Cookie behavior (which proved flaky in-browser despite curl proving both response paths carried it). Cookie still covers subsequent loads; load errors surface as `data.loadError` on the login card instead of silently masquerading as logged-out.
 - **Platform-admin auth via hooks:** `hooks.server.ts` resolves `locals.platformAdmin` from the `platform_session` cookie (=== 'authenticated') on every request; `/admin` load/actions consume `event.locals.platformAdmin` (`requirePlatform(event)`) instead of raw cookie reads. Same central pattern as `pb_token` → `locals.user`.
+- **`isDummyStripe` removed:** real test keys made every dummy branch dead code — and the webhook's `|| !signature` fallback accepted UNSIGNED events (forgeable access grants). Signature is now mandatory (400 without it); settings' simulated endSubscription/portal branches deleted. Dev verification stays via stripe-cli signed events (`pnpm stripe:listen`).
 - **Platform-admin auth hardened (supersedes the constant-cookie version):** `/admin` login now does a real `_superusers.authWithPassword` via PB; the minted superuser JWT goes in `platform_session` (`setPlatformSession` in session.ts). `hooks.server.ts` deviates on `/admin`: verifies the token with `_superusers.authRefresh` → `locals.platformAdmin` (forged values fail authRefresh and get cleared); fam-user pb_token flow skipped on that route. FINAL login shape (user-amended, working): action returns `{success:true}` (no redirect); form's enhance callback does `goto('/admin', { invalidateAll: true })` on success — forcing the load re-run with the fresh cookie; view branches on `data.authenticated`. Verified: real token renders dashboard, forged cookie gets login.
+- **use:enhance redirect gotcha (session-wide lesson):** action-thrown redirects surface as `result.type === 'redirect'` in the RESOLVE callback — handlers checking only `'success'` silently drop them (bit /admin login, pricing choose, and settings billingPortal). Shared fix: `lib/forms.ts` → `handleResult(handler?)` factory follows redirects via `goto`, delegates the rest to the handler or default `update()`. Use it for any form whose action can throw a redirect. Also: enhance is two-stage — `{result}` only exists in the resolve fn, not the submit params (was mis-handled in pricing/signup handlers).