feat(forms): builder UI, management pages, and public fill page (Phase 3)

- components/forms/form-renderer.tsx: one controlled renderer for all 8
  field types, shared by the builder preview and the public page
- components/forms/form-builder.tsx: easy builder — label-only field
  creation (keys auto-derived and de-duped at save), one-click type
  buttons, up/down reordering, inline options editor, live preview;
  edit mode adds publish/close/draft/delete and copy-public-link
- /forms directory, /forms/new, /forms/[id]/edit, /forms/[id]/results
  (CSV download). Server-gated by lib/forms-guard.ts (forms.manage via
  the same RPC the RLS uses; RLS remains the real boundary)
- public app/f/[slug] (outside the app group): getPublicForm serves
  only published public forms — members-only forms are never exposed
  there; waiver consent, anon email capture, signed-in gate for
  public_auth, thank-you state
- sidebar "Forms & waivers" link; sonner toasts (codebase convention)
- ARCHITECTURE + HANDOFF updated

285/285 tests, build clean, all four routes compiled. No deploy.

lib/validations.ts

@@ -569,7 +569,7 @@ export const formKinds = ['form', 'waiver'] as const
 export const formVisibilities = ['public_anon', 'public_auth', 'members'] as const
 export const formStatuses = ['draft', 'published', 'closed'] as const
 
-const formSlug = z
+export const formSlug = z
   .string()
   .min(1, 'Slug is required')
   .max(80, 'Slug must be 80 characters or fewer')
@@ -666,6 +666,8 @@ export const linkSubmissionsSchema = z.object({
   email: emailField(),
 })
 
+export const getPublicFormSchema = z.object({ slug: formSlug })
+
 // ─── Generic ID schemas ──────────────────────────────────────────────────────
 
 export const uuidSchema = z.string().uuid('Invalid ID format')