feat(agent): migrate OpenCode 2 runtime and sandbox tools

Upgrade the runtime and native plugin API to OpenCode 2.0.24. Restore
session-scoped learning, credential renewal, typed project queries and
controlled frontend actions from the legacy Agent.

Replace host Shell execution with an approved Landlock/seccomp executor
and persistent per-session workspaces. Add typed Bocha search and Tianditu
geocoding bridges using the owning session credential. Require a working
kernel sandbox before startup and persist workspace files in deployments.

Validation completed before this commit: TypeScript checks, 150 Bun tests,
Docker build and UID 10001 sandbox execution, native Shell approval and
session recovery. Tianditu succeeded; Bocha currently reports exhausted
account quota. Unrelated investigation-report contract work is excluded.

scripts/start-isolated-integration.ts

@@ -1,10 +1,12 @@
 import { randomBytes } from "node:crypto";
-import { mkdir } from "node:fs/promises";
+import { mkdir, readFile } from "node:fs/promises";
 import { createServer } from "node:net";
 import { dirname, join, resolve } from "node:path";
 import { fileURLToPath } from "node:url";
 
 import dotenv from "dotenv";
+import { serviceOpencodeConfig } from "../src/runtime/opencode2-config.js";
+import { startOpencode2 } from "../src/runtime/opencode2-server.js";
 
 const projectRoot = resolve(dirname(fileURLToPath(import.meta.url)), "..");
 dotenv.config({ path: join(projectRoot, ".local.env"), override: false, quiet: true });
@@ -14,6 +16,7 @@ const opencodePort = readPort("INTEGRATION_OPENCODE_PORT", 14_096);
 const dataRoot = resolve(
   process.env.INTEGRATION_DATA_DIR ?? join(projectRoot, "data", `integration-${agentPort}`),
 );
+process.env.OPENCODE_SKILLS_ROOT_DIR = join(dataRoot, "skills");
 const bridgeToken = process.env.AGENT_INTERNAL_TOKEN?.trim() || randomBytes(32).toString("hex");
 const agentBaseUrl = `http://127.0.0.1:${agentPort}`;
 const opencodeBaseUrl = `http://127.0.0.1:${opencodePort}`;
@@ -25,26 +28,25 @@ await mkdir(dataRoot, { recursive: true });
 const sharedEnvironment = {
   ...process.env,
   AGENT_INTERNAL_TOKEN: bridgeToken,
+  CONVERSATION_WORKSPACE_ROOT: join(dataRoot, "conversation-workspaces"),
+  TJWATER_AGENT_WORKSPACE_ROOT: join(dataRoot, "conversation-workspaces"),
   TJWATER_AGENT_INTERNAL_BASE_URL: agentBaseUrl,
   // Retained for tools loaded by an older compatible OpenCode process.
   TJWATER_AGENT_INTERNAL_TOKEN: bridgeToken,
 };
 
-const opencode = Bun.spawn([
-  "opencode",
-  "serve",
-  "--hostname=127.0.0.1",
-  `--port=${opencodePort}`,
-], {
-  cwd: projectRoot,
+const opencode = await startOpencode2({
+  command: process.env.OPENCODE_COMMAND ?? "opencode2",
+  hostname: "127.0.0.1",
+  port: opencodePort,
+  timeout: 30_000,
+  config: serviceOpencodeConfig(JSON.parse(await readFile(join(projectRoot, "opencode.json"), "utf8"))),
   env: {
     ...sharedEnvironment,
     XDG_CACHE_HOME: join(dataRoot, "xdg-cache"),
     XDG_DATA_HOME: join(dataRoot, "xdg-data"),
     XDG_STATE_HOME: join(dataRoot, "xdg-state"),
   },
-  stderr: "inherit",
-  stdout: "inherit",
 });
 
 let agent: ReturnType<typeof Bun.spawn> | undefined;
@@ -53,7 +55,7 @@ const shutdown = async () => {
   if (shuttingDown) return;
   shuttingDown = true;
   agent?.kill("SIGTERM");
-  opencode.kill("SIGTERM");
+  opencode.close();
   await Promise.allSettled([
     ...(agent ? [agent.exited] : []),
     opencode.exited,
@@ -64,7 +66,7 @@ process.once("SIGINT", () => void shutdown());
 process.once("SIGTERM", () => void shutdown());
 
 try {
-  await waitUntilHealthy(`${opencodeBaseUrl}/global/health`, "OpenCode", opencode);
+  await opencode.client.server.info();
   agent = Bun.spawn([process.execPath, "src/server.ts"], {
     cwd: projectRoot,
     env: {
@@ -73,6 +75,7 @@ try {
       PORT: String(agentPort),
       OPENCODE_MODE: "client",
       OPENCODE_CLIENT_BASE_URL: opencodeBaseUrl,
+      OPENCODE_CLIENT_PASSWORD: opencode.password,
       LLM_REQUEST_AUDIT_LOG_PATH: join(dataRoot, "logs", "llm-request-audit.log"),
       LEARNING_AUDIT_LOG_PATH: join(dataRoot, "logs", "learning-audit.log"),
       MEMORY_STORAGE_DIR: join(dataRoot, "memory"),