Linked positions (Qualified Start): extra wallets on one account, credits pooled, buy-from picker

- accounts/db: positions table + JSON store (add/list/owner/remove; main-wallet and cross-account guards)
- auth verify: asPosition links a second wallet without touching the session; position wallets can't mint a session
- /api/my/positions (chain-refreshed member ids, buyer counts, credits) + remove
- credits pooled across main + positions on /api/me, dashboard, campaigns; campaign charged to the best-funded position
- My line: own positions listed on level 1 as 'You · position N'
- Buy pane: Qualified Start card + Add a position flow + Buy-from picker with connected-wallet guard
- Wallet pane: Your positions card; chatbot answer updated

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>

chatbot.js

@@ -28,7 +28,7 @@ const CANNED = [
   { re: /(how (much|do i) earn|commission|percent|split)/i,
     a: 'Every package splits the same way: 50 percent to the direct sponsor, 20 percent to level 2, 10 percent to level 3, 20 percent to the platform. Those numbers are constants in the contract and cannot be changed. Play with scenarios on the home page calculator. No income is promised; nobody earns unless real ad buying happens.' },
   { re: /(qualif|unlock level|level 2|level 3|pass.?up)/i,
-    a: 'Level 1 is open to every member. Bring 2 buyers of $20 or more and level 2 unlocks; 5 unlock level 3. When a level is not qualified, its share climbs the sponsor line, checking up to 25 positions, and pays the first qualified person. Qualification never expires and cannot be bought.' },
+    a: 'Level 1 is open to every member. Bring 2 buyers of $20 or more and level 2 unlocks; 5 unlock level 3. When a level is not qualified, its share climbs the sponsor line, checking up to 25 positions, and pays the first qualified person. Qualification never expires and cannot be bought. Qualified Start: you may link extra wallets of your own as positions under your account (Buy packages > Qualified Start); each one that buys a $20+ package counts as a qualifying buyer, its credits pool with yours, and 50% of its purchase comes back to your main wallet. Your own money, your own wallets, a faster start, never an income promise.' },
   { re: /(need (a )?wallet|crypto experience|metamask|how (do i|to) join|sign ?up|register)/i,
     a: 'Join free with just your email at https://instantadpay.com/my, no wallet and no password needed. Your wallet only comes out when you buy a package or switch on payouts, and the site walks you through it.' },
   { re: /(referral link|invite link|share link|refer)/i,