refactor(auth): route browser paste login through /perplexity-login

The perplexity_search tool no longer prompts for pasted browser
credentials mid-search; /perplexity-login --browser is the single
entry point for that flow. Drop the now-unused promptForBrowserAuth
option and its Cloudflare-challenge fallback from authenticate().

src/auth/login.ts

@@ -39,7 +39,6 @@ export interface AuthenticateOptions {
   signal?: AbortSignal;
   promptForEmail?: () => Promise<string | null | undefined>;
   promptForOtp?: (email: string) => Promise<string | null | undefined>;
-  promptForBrowserAuth?: () => Promise<string | null | undefined>;
 }
 
 function normalizeInput(value: string | null | undefined): string | null {
@@ -91,16 +90,6 @@ export async function saveBrowserAuthInput(input: string): Promise<StoredToken>
   return credentials;
 }
 
-async function promptForBrowserCredentials(
-  options: AuthenticateOptions,
-): Promise<StoredToken | null> {
-  const input = normalizeInput(await options.promptForBrowserAuth?.());
-  if (!input) {
-    return null;
-  }
-  return saveBrowserAuthInput(input);
-}
-
 function buildAuthHeaders(includeJsonContentType = false): Record<string, string> {
   return {
     Accept: "application/json",
@@ -297,11 +286,6 @@ export async function authenticate(options: AuthenticateOptions = {}): Promise<S
     normalizeInput(process.env.PI_PERPLEXITY_EMAIL) ??
     normalizeInput(await options.promptForEmail?.());
   if (!email) {
-    const browserCredentials = await promptForBrowserCredentials(options);
-    if (browserCredentials) {
-      return browserCredentials;
-    }
-
     throw new AuthError(
       "NO_TOKEN",
       `Could not find a desktop token, browser token/cookie, or email for OTP fallback. ${DESKTOP_AUTH_HELP} ${OTP_AUTH_HELP} ${BROWSER_AUTH_HELP}`,
@@ -317,13 +301,6 @@ export async function authenticate(options: AuthenticateOptions = {}): Promise<S
       throw error;
     }
 
-    if (error instanceof BrowserChallengeError) {
-      const browserCredentials = await promptForBrowserCredentials(options);
-      if (browserCredentials) {
-        return browserCredentials;
-      }
-    }
-
     throw new AuthError(
       "EXTRACTION_FAILED",
       `Email OTP authentication failed: ${errorMessage(error)}. ${OTP_AUTH_HELP} ${BROWSER_AUTH_HELP}`,

src/commands/login.ts

@@ -107,7 +107,7 @@ export function registerPerplexityCommands(pi: ExtensionAPI): void {
           return;
         }
 
-        await authenticate({ promptForEmail, promptForOtp, promptForBrowserAuth });
+        await authenticate({ promptForEmail, promptForOtp });
         ctx.ui.notify("Perplexity login successful. Token saved.", "info");
       } catch (error) {
         if (error instanceof AuthError && error.code === "NO_TOKEN") {

src/index.ts

@@ -5,7 +5,6 @@ import { Type } from "@sinclair/typebox";
 import { registerPerplexityConfigCommand } from "./commands/config.js";
 import { registerPerplexityCommands } from "./commands/login.js";
 
-import { browserLoginInstructions } from "./auth/browser.js";
 import { authenticate } from "./auth/login.js";
 import { loadConfig, resolveSearchDefaults } from "./config.js";
 import { formatForLLM } from "./search/format.js";
@@ -58,13 +57,6 @@ export default function (pi: ExtensionAPI) {
           ...(signal !== undefined ? { signal } : {}),
           promptForEmail: async () => promptInput("Perplexity email", "you@example.com"),
           promptForOtp: async (email) => promptInput(`Enter OTP sent to ${email}`, "123456"),
-          promptForBrowserAuth: async () => {
-            ctx?.ui?.notify?.(browserLoginInstructions(), "info");
-            return promptInput(
-              "Paste copied cURL command or Cookie header",
-              "curl 'https://www.perplexity.ai/' -H 'Cookie: ...'",
-            );
-          },
         });
 
         if (signal?.aborted) {