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>

db.js

@@ -120,6 +120,15 @@ async function bootstrap() {
   await alterSafe('ALTER TABLE campaigns ADD COLUMN expires BIGINT NULL'); // featured rotation end time
   await alterSafe('ALTER TABLE campaigns ADD COLUMN starts BIGINT NULL');  // featured run start (booked day)
   await alterSafe('ALTER TABLE campaigns ADD COLUMN house TINYINT NOT NULL DEFAULT 0'); // admin house ad: free, never charged
+  // linked positions: extra wallets owned by one email account (Qualified Start).
+  // Each is its own on-chain member sponsored by the account's main member.
+  await q(`CREATE TABLE IF NOT EXISTS positions (
+    address VARCHAR(64) PRIMARY KEY,
+    email VARCHAR(190) NOT NULL,
+    member_id INT NOT NULL DEFAULT 0,
+    created BIGINT NOT NULL,
+    INDEX (email)
+  ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4`);
   await q(`CREATE TABLE IF NOT EXISTS visit_seen (
     campaign_id INT NOT NULL,
     email VARCHAR(190) NOT NULL,