Extract groombook/api from monorepo with CI workflow

- Add source code from apps/api
- Add packages/db and packages/types workspace dependencies
- Add GitHub Actions CI workflow (lint, typecheck, test, docker)
- Generate pnpm-lock.yaml
- Add .gitignore

Co-Authored-By: Paperclip <noreply@paperclip.ing>

src/middleware/portalSession.ts

@@ -0,0 +1,40 @@
+import type { MiddlewareHandler } from "hono";
+import { and, eq, getDb, impersonationSessions } from "@groombook/db";
+
+export interface PortalEnv {
+  Variables: {
+    portalClientId: string;
+    portalSessionId: string;
+  };
+}
+
+/**
+ * Validates the X-Impersonation-Session-Id header against the impersonationSessions table.
+ * Must be applied to all portal routes.
+ *
+ * Reads x-session-id from request headers, queries impersonationSessions for a row where
+ * id = sessionId AND status = 'active', and checks session.expiresAt > new Date().
+ * Returns 401 if session is invalid/missing/expired.
+ * On success, sets c.set("portalClientId", session.clientId) and c.set("portalSessionId", session.id).
+ */
+export const validatePortalSession: MiddlewareHandler<PortalEnv> = async (c, next) => {
+  const sessionId = c.req.header("X-Impersonation-Session-Id");
+  if (!sessionId) {
+    return c.json({ error: "Unauthorized" }, 401);
+  }
+
+  const db = getDb();
+  const [session] = await db
+    .select()
+    .from(impersonationSessions)
+    .where(and(eq(impersonationSessions.id, sessionId), eq(impersonationSessions.status, "active")))
+    .limit(1);
+
+  if (!session || session.expiresAt <= new Date()) {
+    return c.json({ error: "Unauthorized" }, 401);
+  }
+
+  c.set("portalClientId", session.clientId);
+  c.set("portalSessionId", session.id);
+  await next();
+};