feat(auth): Integrate Cloudflare Turnstile bot protection and enhance swarm tracking

- Add Cloudflare Turnstile integration for login and registration forms
- Create turnstile verification utility with server-side token validation
- Add turnstile_site_key and turnstile_secret_key fields to nodes table
- Implement admin panel UI for configuring Turnstile keys in settings
- Update login and register API routes to verify Turnstile tokens
- Expose turnstile_site_key via GET /api/node endpoint for frontend
- Add admin endpoint to save and update Turnstile configuration
- Create remote_likes and remote_reposts tables for federated interaction tracking
- Add swarm reply metadata fields (swarm_reply_to_id, swarm_reply_to_content, swarm_reply_to_author) to posts table
- Add comprehensive TURNSTILE_SETUP.md documentation with setup instructions and security notes
- Create database migration 0007 with schema updates and indexes
- Protects against bot registrations and automated attacks on federated nodes

src/app/api/admin/node/route.ts

@@ -27,6 +27,8 @@ export async function PATCH(req: NextRequest) {
                 faviconUrl: data.faviconUrl,
                 accentColor: data.accentColor,
                 isNsfw: data.isNsfw ?? false,
+                turnstileSiteKey: data.turnstileSiteKey,
+                turnstileSecretKey: data.turnstileSecretKey,
             }).returning();
         } else {
             [node] = await db.update(nodes)
@@ -40,6 +42,8 @@ export async function PATCH(req: NextRequest) {
                     faviconUrl: data.faviconUrl,
                     accentColor: data.accentColor,
                     isNsfw: data.isNsfw ?? node.isNsfw,
+                    turnstileSiteKey: data.turnstileSiteKey !== undefined ? data.turnstileSiteKey : node.turnstileSiteKey,
+                    turnstileSecretKey: data.turnstileSecretKey !== undefined ? data.turnstileSecretKey : node.turnstileSecretKey,
                     updatedAt: new Date(),
                 })
                 .where(eq(nodes.id, node.id))