chore(cl-6815): trim unreachable usage formatters, demo, kickoff stub

Decision: usage display is not a product surface — delete fetch/format helpers and their tests rather than wiring them in. Keep only the live auth-header helpers used by oauth-scope-check, renamed usage.ts -> auth-headers.ts. Delete src/tui/demo.ts (410 lines, README-only reference) and the unreferenced workflows/kickoff stub. Net-negative.

Author: TheGreatAxios

src/auth/codex/auth-headers.ts

@@ -0,0 +1,18 @@
+import { CODEX_CLIENT_VERSION, CODEX_ORIGINATOR } from "./constants.js";
+
+export function codexAuthHeadersForToken(
+  token: {
+    readonly access: string;
+    readonly accountId?: string | undefined;
+  },
+  commandName: string,
+): Record<string, string> {
+  const headers: Record<string, string> = {
+    authorization: `Bearer ${token.access}`,
+    originator: CODEX_ORIGINATOR,
+    "user-agent": `${commandName} (${CODEX_ORIGINATOR}/${CODEX_CLIENT_VERSION})`,
+  };
+  if (token.accountId !== undefined)
+    headers["chatgpt-account-id"] = token.accountId;
+  return headers;
+}

src/auth/codex/constants.ts

@@ -11,10 +11,8 @@ const codexRedirect = new URL(CODEX_REDIRECT_URI);
 export const CODEX_CALLBACK_PORT = Number(codexRedirect.port);
 export const CODEX_CALLBACK_PATH = codexRedirect.pathname;
 
-// Live usage/quota for the prepaid plan (window %, reset, credits) and the
-// account's available model catalog. The models endpoint requires a
+// The account's available model catalog. The models endpoint requires a
 // client_version query param.
-export const CODEX_USAGE_PATH = "/codex/usage";
 export const CODEX_MODELS_PATH = "/codex/models";
 export const CODEX_CLIENT_VERSION = "0.50.0";
 

src/auth/codex/usage.ts

@@ -19,11 +19,11 @@ import {
 } from "./codex/constants.js";
 import { refreshStagedCodexTokens } from "./codex/session.js";
 import type { CodexTokens } from "./codex/store.js";
-import { codexAuthHeadersForToken } from "./codex/usage.js";
+import { codexAuthHeadersForToken } from "./codex/auth-headers.js";
 import { XAI_BASE_URL, XAI_TOKEN_TIMEOUT_MS } from "./xai/constants.js";
 import { refreshStagedXaiTokens } from "./xai/session.js";
 import type { XaiTokens } from "./xai/store.js";
-import { xaiAuthHeadersForToken } from "./xai/usage.js";
+import { xaiAuthHeadersForToken } from "./xai/auth-headers.js";
 
 export type OAuthScopeCheckKind = "codex" | "xai";
 

src/auth/oauth-scope-check.ts

@@ -0,0 +1,21 @@
+import { xaiUserIdFromAccessToken } from "@corbits/xai-provider";
+
+import {
+  XAI_CLIENT_IDENTIFIER,
+  XAI_CLIENT_VERSION,
+  XAI_USER_AGENT,
+} from "./constants.js";
+
+export function xaiAuthHeadersForToken(token: {
+  readonly access: string;
+}): Record<string, string> {
+  const headers: Record<string, string> = {
+    authorization: `Bearer ${token.access}`,
+    "user-agent": XAI_USER_AGENT,
+    "x-grok-client-identifier": XAI_CLIENT_IDENTIFIER,
+    "x-grok-client-version": XAI_CLIENT_VERSION,
+  };
+  const userId = xaiUserIdFromAccessToken(token.access);
+  if (userId !== undefined) headers["x-grok-user-id"] = userId;
+  return headers;
+}

src/auth/xai/auth-headers.ts

@@ -22,9 +22,7 @@ export const XAI_CLIENT_IDENTIFIER = "grok-shell";
 export const XAI_CLIENT_VERSION = "0.2.93";
 export const XAI_USER_AGENT = "grok-shell/0.2.93 (macos; aarch64)";
 
-export const XAI_BILLING_URL = "https://cli-chat-proxy.grok.com/v1/billing";
-
-// Cap every token and billing request to the xAI proxy. The refresh runs on the
+// Cap every token request to the xAI proxy. The refresh runs on the
 // send path before the inference fetch arms its inactivity/total timers, so a
 // stalled token endpoint would otherwise freeze the agent at turn 0.
 export const XAI_TOKEN_TIMEOUT_MS = 15_000;