chore(app-server): delete v1 RPC methods and notifications (#13375)

## Summary
This removes the old app-server v1 methods and notifications we no
longer need, while keeping the small set the main codex app client still
depends on for now.

The remaining legacy surface is:
- `initialize`
- `getConversationSummary`
- `getAuthStatus`
- `gitDiffToRemote`
- `fuzzyFileSearch`
- `fuzzyFileSearch/sessionStart`
- `fuzzyFileSearch/sessionUpdate`
- `fuzzyFileSearch/sessionStop`

And the raw `codex/event/*` notifications emitted from core. These
notifications will be removed in a followup PR.

## What changed
- removed deprecated v1 request variants from the protocol and
app-server dispatcher
- removed deprecated typed notifications: `authStatusChange`,
`loginChatGptComplete`, and `sessionConfigured`
- updated the app-server test client to use v2 flows instead of deleted
v1 flows
- deleted legacy-only app-server test suites and added focused coverage
for `getConversationSummary`
- regenerated app-server schema fixtures and updated the MCP interface
docs to match the remaining compatibility surface

## Testing
- `just write-app-server-schema`
- `cargo test -p codex-app-server-protocol`
- `cargo test -p codex-app-server`

codex-rs/app-server-protocol/src/export.rs

@@ -45,36 +45,9 @@ const SPECIAL_DEFINITIONS: &[&str] = &[
     "ServerRequest",
 ];
 const FLAT_V2_SHARED_DEFINITIONS: &[&str] = &["ClientRequest", "EventMsg", "ServerNotification"];
-const V1_CLIENT_REQUEST_METHODS: &[&str] = &[
-    "newConversation",
-    "getConversationSummary",
-    "listConversations",
-    "resumeConversation",
-    "forkConversation",
-    "archiveConversation",
-    "sendUserMessage",
-    "sendUserTurn",
-    "interruptConversation",
-    "addConversationListener",
-    "removeConversationListener",
-    "gitDiffToRemote",
-    "loginApiKey",
-    "loginChatGpt",
-    "cancelLoginChatGpt",
-    "logoutChatGpt",
-    "getAuthStatus",
-    "getUserSavedConfig",
-    "setDefaultModel",
-    "getUserAgent",
-    "userInfo",
-    "execOneOffCommand",
-];
-const EXCLUDED_SERVER_NOTIFICATION_METHODS_FOR_JSON: &[&str] = &[
-    "authStatusChange",
-    "loginChatGptComplete",
-    "sessionConfigured",
-    "rawResponseItem/completed",
-];
+const V1_CLIENT_REQUEST_METHODS: &[&str] =
+    &["getConversationSummary", "gitDiffToRemote", "getAuthStatus"];
+const EXCLUDED_SERVER_NOTIFICATION_METHODS_FOR_JSON: &[&str] = &["rawResponseItem/completed"];
 
 #[derive(Clone)]
 pub struct GeneratedSchema {