feat: add typescript monorepo with pnpm workspaces and prisma database package

- root package.json + pnpm-workspace.yaml + tsconfig.base.json
- packages/types: canonical enums (TenantStatus, AgentState)
- packages/shared: re-exports types, base for future utilities
- packages/database: Prisma 7 schema with driver adapter (pg), initial
  tenants table matching agente.md section 29, first migration applied

packages/types/src/index.ts

@@ -0,0 +1,18 @@
+export enum TenantStatus {
+  TRIAL = "TRIAL",
+  ACTIVE = "ACTIVE",
+  SUSPENDED = "SUSPENDED",
+  PAST_DUE = "PAST_DUE",
+  CANCELLED = "CANCELLED",
+}
+
+export enum AgentState {
+  OFFLINE = "OFFLINE",
+  LOGGED_IN = "LOGGED_IN",
+  AVAILABLE = "AVAILABLE",
+  RESERVED = "RESERVED",
+  RINGING = "RINGING",
+  IN_CALL = "IN_CALL",
+  WRAP_UP = "WRAP_UP",
+  PAUSED = "PAUSED",
+}