fix(agent): isolate conversation workspaces

src/runtime/opencode.ts

@@ -2,11 +2,14 @@ import {
   createOpencode,
   type OpencodeClient,
 } from "@opencode-ai/sdk/v2";
+import { randomUUID } from "node:crypto";
 import { existsSync, readFileSync } from "node:fs";
+import { chmod, mkdir, rmdir } from "node:fs/promises";
 import { resolve } from "node:path";
 
 import { config } from "../config.js";
 import { logger } from "../logger.js";
+import { ensureDirectory } from "../utils/fileStore.js";
 import {
   cleanupExpiredToolOutputs,
   resolveOpencodeToolOutputDirectory,
@@ -126,12 +129,46 @@ export class OpencodeRuntimeAdapter {
     }
   }
 
-  async createSession(title?: string) {
+  async createSession(
+    title?: string,
+    options: {
+      conversationWorkspace?: boolean;
+      workspaceRoot?: string;
+    } = {},
+  ) {
     const client = await this.ensureClient();
-    const response = await client.session.create({
-      title,
-    });
-    return requireData(response.data, "session.create");
+    if (!options.conversationWorkspace) {
+      const response = await client.session.create({ title });
+      return requireData(response.data, "session.create");
+    }
+
+    const workspaceRoot = resolve(
+      options.workspaceRoot ?? config.RESULT_REF_IMPORT_DIR,
+    );
+    const directory = resolve(workspaceRoot, `conversation-${randomUUID()}`);
+    await ensureDirectory(workspaceRoot);
+    await chmod(workspaceRoot, 0o700);
+    await mkdir(directory, { mode: 0o700 });
+    try {
+      const response = await client.session.create({
+        directory,
+        title,
+        permission: [
+          { permission: "read", pattern: `${directory}/**`, action: "allow" },
+          { permission: "edit", pattern: `${directory}/**`, action: "ask" },
+        ],
+      });
+      return requireData(response.data, "session.create");
+    } catch (error) {
+      await rmdir(directory).catch(() => undefined);
+      throw error;
+    }
+  }
+
+  async getSession(sessionId: string) {
+    const client = await this.ensureClient();
+    const response = await client.session.get({ sessionID: sessionId });
+    return requireData(response.data, "session.get");
   }
 
   async sendPrompt(sessionId: string, text: string) {