ci: fix port 5432 collision and include read-only-prisma helper

- Remove host port mappings from postgres/redis services in ci.yml;
  QNAP runner already occupies 5432. Use service DNS names
  (postgres/redis) instead of localhost for DB/Redis URLs.
- Track packages/api/src/lib/read-only-prisma.ts which was imported
  by assistant-tools.ts but never committed, breaking check:imports.

packages/api/src/lib/read-only-prisma.ts

@@ -0,0 +1,57 @@
+/**
+ * Read-only Prisma proxy.
+ *
+ * Wraps a PrismaClient and blocks write operations at the application level.
+ * Used to enforce read-only access for AI read-tools (EGAI 4.1.1.2 / IAAI 3.6.22).
+ */
+
+import type { prisma } from "@capakraken/db";
+
+type PrismaClient = typeof prisma;
+
+const WRITE_METHODS = new Set([
+  "create",
+  "createMany",
+  "createManyAndReturn",
+  "update",
+  "updateMany",
+  "upsert",
+  "delete",
+  "deleteMany",
+]);
+
+function readOnlyModelProxy(model: Record<string, unknown>, modelName: string): unknown {
+  return new Proxy(model, {
+    get(target, prop) {
+      if (typeof prop === "string" && WRITE_METHODS.has(prop)) {
+        return () => {
+          throw new Error(
+            `Write operation "${prop}" on "${modelName}" not permitted on read-only context`,
+          );
+        };
+      }
+      return Reflect.get(target, prop);
+    },
+  });
+}
+
+export function createReadOnlyProxy(client: PrismaClient): PrismaClient {
+  return new Proxy(client, {
+    get(target, prop) {
+      const value = Reflect.get(target, prop);
+      // If accessing a model delegate (object with findMany, etc.), wrap it
+      if (value && typeof value === "object" && "findMany" in (value as Record<string, unknown>)) {
+        return readOnlyModelProxy(value as Record<string, unknown>, String(prop));
+      }
+      // Block $executeRaw and $executeRawUnsafe at the client level
+      if (prop === "$executeRaw" || prop === "$executeRawUnsafe") {
+        return () => {
+          throw new Error(
+            `Raw write operation "${String(prop)}" not permitted on read-only context`,
+          );
+        };
+      }
+      return value;
+    },
+  }) as PrismaClient;
+}