refactor(builder): move zalo, tiktok, telegram, webchat, smtp data access into business

[realcodesiman]

Summary

• Removes every direct db.* call from the non-Meta channel integrations in the builder (Zalo, TikTok, Telegram, webchat, SMTP, Google Sheets disconnect, the AI-integration gate, and the public webchat widget page) per .agents/rules/data-access.md.
• One of seven parallel scope PRs following feat(contacts): cover full public API for MCP, move logic into business services #1093 (contacts); all are based on main. This one needs no barrel edits at all.

Changes

• packages/business/src/integration-{zalo,tiktok,telegram,webchat,smtp,google-sheet,integration}/service.ts: new connect/disconnect/list*/findBy*/update methods appended to the existing services. Disconnect methods open their own transaction when no tx is supplied.
• Telegram connect keeps webhook registration inside the transaction through an onConnected callback, so a failed registration still rolls back (pinned by packages/business/__tests__/integration-telegram-service.test.ts).
• SMTP: reads/writes moved to business; transport verification and host/port resolution stay in apps/builder/src/features/integration-smtp/lib/ because business does not depend on @chatbotx.io/mail or @chatbotx.io/integration-smtp. The ad-hoc services/ directory is removed.
• Dead exports removed after grep confirmed zero callers: findIntegrationZalo, findIntegrationTiktok, findIntegrationTelegram, findIntegrationSmtp, listAIIntegrations.
• Tests re-pointed to the service boundary; new packages/business/__tests__/integration-{zalo,tiktok,telegram,webchat,smtp}-service.test.ts, apps/builder/__tests__/{smtp-actions-thin,google-sheets-disconnect-action}.test.ts.

Notes for reviewers

• Not-found messages differ slightly where an existing finder was reused (e.g. "Integration Zalo OA not found"); no test or caller asserts those strings.
• Follow-up (out of scope): integration-zalo/actions/toggle-tag-sync.action.ts still uses db and was not in this scope's file list.

Test plan

• pnpm --filter @chatbotx.io/database check-types && test
• pnpm --filter @chatbotx.io/business check-types && test (only the pre-existing ads-conversion-rule.service.test.ts failures remain, also red on main)
• pnpm --filter builder check-types && test
• pnpm lint
• Manual: connect + disconnect a Telegram bot; open a public webchat widget page; load /settings/channels/{zalo,tiktok,telegram,smtp,webchat}