feat(codex): share sessions across terminal and web

Use one native app-server for terminal, Web and phone clients while retaining the existing CLI and Runner lifecycle.

Synchronize native queues, permissions, question history and steering state; preserve explicit permission precedence and per-turn usage models. Resume inactive clear commands through Runner and reject independent child cold resumes.

Add shared-runtime regression tests, generated protocol fixtures and lifecycle documentation.

cli/src/codex/utils/appServerPermissionAdapter.ts

@@ -22,6 +22,7 @@ type ElicitationSchemaProperty = {
 };
 
 type UserInputAnswer = Record<string, string[]> | Record<string, { answers: string[] }>;
+export const IGNORE_SHARED_REQUEST = Symbol('ignore-shared-request');
 
 function asRecord(value: unknown): Record<string, unknown> | null {
     if (!value || typeof value !== 'object') {
@@ -376,8 +377,9 @@ function isHapiBridgeElicitation(params: unknown): boolean {
 }
 
 export function registerAppServerPermissionHandlers(args: {
-    client: CodexAppServerClient;
-    permissionHandler: CodexPermissionHandler;
+    client: Pick<CodexAppServerClient, 'registerRequestHandler'>;
+    permissionHandler: Pick<CodexPermissionHandler, 'handleToolCall'>;
+    shared?: boolean;
     getPermissionMode?: () => CodexPermissionMode | undefined;
     onUserInputRequest?: (request: { id: string; input: unknown }) => Promise<
         | { decision: 'accept'; answers: UserInputAnswer }
@@ -504,6 +506,7 @@ export function registerAppServerPermissionHandlers(args: {
 
         const input = buildElicitationUserInput(params);
         if (!onUserInputRequest || !input) {
+            if (args.shared) return IGNORE_SHARED_REQUEST;
             logger.debug('[CodexAppServer] Cancelling unsupported MCP elicitation request', {
                 serverName: record.serverName,
                 mode: request.mode,

cli/src/codex/utils/buildHapiMcpBridge.ts

@@ -45,6 +45,7 @@ export interface HapiMcpBridge {
 }
 
 export interface HapiMcpBridgeOptions {
+    exportSessionEnv?: boolean;
     emitTitleSummary?: boolean;
     enableChangeTitle?: boolean;
     skillLookup?: {
@@ -76,7 +77,7 @@ export async function buildHapiMcpBridge(
         }
     }
     // Belt-and-suspenders: onMaterialized already exports; keep env set for non-lazy too.
-    exportHapiSessionEnv(client.sessionId);
+    if (options.exportSessionEnv !== false) exportHapiSessionEnv(client.sessionId);
 
     const happyServer = await startHappyServer(client, {
         emitTitleSummary: options.emitTitleSummary,