fix(cli): add API Key option to qwen auth interactive menu (#3624)

* fix(cli): add "API Key" option to `qwen auth` interactive menu

The `qwen auth` CLI command only showed 2 options (Coding Plan, Qwen OAuth),
while the interactive `/auth` dialog showed 3 (Coding Plan, API Key, Qwen OAuth).
Users following the README instructions to configure OpenRouter/Fireworks via
`qwen auth` had no API Key entry point.

- Add "API Key" option to the `runInteractiveAuth` menu with two sub-paths:
  "Alibaba Cloud ModelStudio Standard API Key" (guided flow) and
  "Custom API Key" (prints docs link)
- Add `qwen auth api-key` yargs subcommand for direct access
- Extract `createMinimalArgv` / `loadAuthConfig` helpers to eliminate duplicated
  CliArgs boilerplate
- Extract `promptForInput` to share raw-mode stdin logic between `promptForKey`
  and `promptForModelIds`
- Improve `showAuthStatus` to distinguish Coding Plan, Standard API Key, and
  generic OpenAI-compatible configurations
- Align menu labels and descriptions with the interactive `/auth` dialog

Closes #3413

Co-authored-by: Qwen-Coder <qwen-coder@alibabacloud.com>

* docs: add `qwen auth api-key` to auth subcommand tables

Update documentation to reflect the new `qwen auth api-key` subcommand:
- auth.md: add to subcommands table, examples, and interactive menu display
- commands.md: add to CLI Auth Subcommands table
- quickstart.md: add to quick-reference command table

* fix(cli): restore incomplete Coding Plan warning in showAuthStatus

When selectedType is USE_OPENAI and Coding Plan metadata exists but
the API key is missing, show the incomplete warning instead of falling
through to the generic "OpenAI-compatible" status.

* refactor(cli): use endpoint constants in region selector and fix status formatting

- Use ALIBABA_STANDARD_API_KEY_ENDPOINTS constants for region
  descriptions instead of hardcoded URLs
- Restore trailing newline in showAuthStatus "no auth" command list
  for consistent spacing

* fix(cli): determine active auth method from model config in showAuthStatus

Previously showAuthStatus checked which env keys exist to determine
the auth method, causing false reports when users switch providers
(e.g., Coding Plan key still present after switching to Standard API Key).

Now it inspects the active model's provider config (baseUrl/envKey) to
determine the actual method, and validates the corresponding key exists:
- Coding Plan: check via isCodingPlanConfig + CODING_PLAN_ENV_KEY
- Standard API Key: check via DASHSCOPE_STANDARD_API_KEY_ENV_KEY + endpoints
- Generic OpenAI-compatible: check if the model's envKey is set

Also clear stale Coding Plan metadata (codingPlan.region/version and
process.env) when switching to Standard API Key.

* fix(cli): add legacy fallback in showAuthStatus and clear persisted Coding Plan env

- When no active model config is found (legacy setups without
  modelProviders), fall back to env key / metadata checks for
  Coding Plan status detection. Fixes CI test failures.
- When activeConfig exists but has no envKey, report incomplete
  status instead of false positive "Configured".
- Clear persisted env.BAILIAN_CODING_PLAN_API_KEY from settings
  when switching to Standard API Key, not just process.env.

* fix(cli): also remove Coding Plan model entries when switching to Standard API Key

When switching to Standard API Key, filter out existing Coding Plan
model entries from modelProviders.openai in addition to old Standard
entries. Previously these were preserved but their credential source
(BAILIAN_CODING_PLAN_API_KEY) was cleared, leaving broken model
entries visible in /model.

---------

Co-authored-by: Qwen-Coder <qwen-coder@alibabacloud.com>

docs/users/configuration/auth.md

@@ -330,6 +330,7 @@ You'll see a selector with arrow-key navigation:
 Select authentication method:
 
   Alibaba Cloud Coding Plan - Paid · Up to 6,000 requests/5 hrs · All Alibaba Cloud Coding Plan Models
+  API Key - Bring your own API key
   Qwen OAuth - Discontinued — switch to Coding Plan or API Key
 
 (Use ↑ ↓ arrows to navigate, Enter to select, Ctrl+C to exit)
@@ -340,9 +341,10 @@ Select authentication method:
 | Command                                              | Description                                       |
 | ---------------------------------------------------- | ------------------------------------------------- |
 | `qwen auth`                                          | Interactive authentication setup                  |
-| `qwen auth qwen-oauth`                               | Authenticate with Qwen OAuth                      |
 | `qwen auth coding-plan`                              | Authenticate with Alibaba Cloud Coding Plan       |
 | `qwen auth coding-plan --region china --key sk-sp-…` | Non-interactive Coding Plan setup (for scripting) |
+| `qwen auth api-key`                                  | Authenticate with an API key                      |
+| `qwen auth qwen-oauth`                               | Authenticate with Qwen OAuth (discontinued)       |
 | `qwen auth status`                                   | Show current authentication status                |
 
 **Examples:**
@@ -357,6 +359,9 @@ qwen auth coding-plan
 # Set up Coding Plan non-interactively (useful for CI/scripting)
 qwen auth coding-plan --region china --key sk-sp-xxxxxxxxx
 
+# Set up API key (ModelStudio Standard or custom provider)
+qwen auth api-key
+
 # Check your current auth configuration
 qwen auth status
 ```