fix: correct doc examples with valid Codex modes and update stable API list

- Replace invalid Codex mode values ("plan", "build") with valid ones
  ("auto", "full-access") in agent-sessions.mdx and sdk-overview.mdx
- Update CLAUDE.md stable method enumerations to include new session
  config methods (setSessionMode, setSessionModel, etc.)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

CLAUDE.md

@@ -54,8 +54,8 @@
   - `acp-http-client`: protocol-pure ACP-over-HTTP (`/v1/acp`) with no Sandbox-specific HTTP helpers.
   - `sandbox-agent`: `SandboxAgent` SDK wrapper that combines ACP session operations with Sandbox control-plane and filesystem helpers.
 - `SandboxAgent` entry points are `SandboxAgent.connect(...)` and `SandboxAgent.start(...)`.
-- Stable Sandbox session methods are `createSession`, `resumeSession`, `resumeOrCreateSession`, `destroySession`, `sendSessionMethod`, and `onSessionEvent`.
-- `Session` helpers are `prompt(...)`, `send(...)`, and `onEvent(...)`.
+- Stable Sandbox session methods are `createSession`, `resumeSession`, `resumeOrCreateSession`, `destroySession`, `sendSessionMethod`, `onSessionEvent`, `setSessionMode`, `setSessionModel`, `setSessionThoughtLevel`, `setSessionConfigOption`, `getSessionConfigOptions`, and `getSessionModes`.
+- `Session` helpers are `prompt(...)`, `send(...)`, `onEvent(...)`, `setMode(...)`, `setModel(...)`, `setThoughtLevel(...)`, `setConfigOption(...)`, `getConfigOptions()`, and `getModes()`.
 - Cleanup is `sdk.dispose()`.
 
 ### Docs Source Of Truth

docs/agent-sessions.mdx

@@ -91,7 +91,7 @@ Set the model, mode, or thought level on a session at creation time or after:
 const session = await sdk.createSession({
   agent: "codex",
   model: "gpt-5.3-codex",
-  mode: "plan",
+  mode: "auto",
   thoughtLevel: "high",
 });
 ```
@@ -99,7 +99,7 @@ const session = await sdk.createSession({
 ```ts
 // After creation
 await session.setModel("gpt-5.2-codex");
-await session.setMode("build");
+await session.setMode("full-access");
 await session.setThoughtLevel("medium");
 ```
 

docs/sdk-overview.mdx

@@ -111,7 +111,7 @@ const session = await sdk.createSession({
 });
 
 await session.setModel("gpt-5.2-codex");
-await session.setMode("plan");
+await session.setMode("auto");
 
 const options = await session.getConfigOptions();
 const modes = await session.getModes();