feat: scrip engine implementation — real SMTP, webhooks, DB actions

- config.ts: add SMTP_HOST, SMTP_PORT, SMTP_USER, SMTP_PASS, SMTP_FROM
- engine.ts: prepare() queries real scrips from DB, matches by queue_id + condition_type, loads lifecycle for OnResolve context, renders Handlebars templates, builds PreparedScrip. commit() dispatches to real action executors.
- actions.ts: SendEmail via nodemailer SMTP, Webhook via fetch POST, SetCustomField writes to custom_field_values table
- conditions.ts: OnResolve uses LifecycleValidator.isResolvedStatus()
- tickets.ts: updated to pass lifecycleDef context to scrip engine
- nodemailer installed
- Port changed to 9876 (8080 occupied by Apache)

Verification: bun run src/index.ts starts server, GET /health returns {"status":"ok","version":"0.1.0"}

.env.example

@@ -1,3 +1,3 @@
 DATABASE_URL=postgres://tessera:password@localhost:5432/tessera
 SERVER_HOST=127.0.0.1
-SERVER_PORT=8080
+SERVER_PORT=9876