v0.9.88 major change sqlite to postgres

backend/src/models/migrations/003_tenants.sql

@@ -0,0 +1,31 @@
+-- Migration 003: Tenant registry (JAMA-HOST mode)
+--
+-- This table lives in the 'public' schema and is the source of truth for
+-- all tenants in host mode. In selfhost mode this table exists but stays
+-- empty — it has no effect on anything.
+
+CREATE TABLE IF NOT EXISTS tenants (
+  id           SERIAL PRIMARY KEY,
+  slug         TEXT NOT NULL UNIQUE,        -- used as schema name: tenant_{slug}
+  name         TEXT NOT NULL,               -- display name
+  schema_name  TEXT NOT NULL UNIQUE,        -- actual Postgres schema: tenant_{slug}
+  custom_domain TEXT,                       -- optional: team1.example.com
+  plan         TEXT NOT NULL DEFAULT 'chat', -- chat | brand | team
+  status       TEXT NOT NULL DEFAULT 'active', -- active | suspended
+  admin_email  TEXT,                        -- first admin email for this tenant
+  created_at   TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+  updated_at   TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE INDEX IF NOT EXISTS idx_tenants_slug          ON tenants(slug);
+CREATE INDEX IF NOT EXISTS idx_tenants_custom_domain ON tenants(custom_domain) WHERE custom_domain IS NOT NULL;
+CREATE INDEX IF NOT EXISTS idx_tenants_status        ON tenants(status);
+
+-- Auto-update updated_at
+DO $$ BEGIN
+  IF NOT EXISTS (SELECT 1 FROM pg_trigger WHERE tgname = 'trg_tenants_updated_at') THEN
+    CREATE TRIGGER trg_tenants_updated_at
+      BEFORE UPDATE ON tenants
+      FOR EACH ROW EXECUTE FUNCTION set_updated_at();
+  END IF;
+END $$;