[bug] vision describe: default base URL is the Coding Plan endpoint → HTTP 404 for all VL/OCR models #241

Environment

• CLI: bl 2.1.0
• Skill: 2.1.0
• Node: v22.23.3
• OS: Linux 5.15.0-198-generic x86_64 (Ubuntu)
• Region: cn (domestic)

Reproduce

bl vision describe without an explicit --base-url posts to
https://coding.dashscope.aliyuncs.com/compatible-mode/v1/chat/completions,
which does not serve VL/OCR models, so the request always 404s.

# fails
bl vision describe --image ./test.png --model qwen3.5-ocr --prompt "Output the text" --verbose

# identical command + explicit public endpoint succeeds
bl vision describe --image ./test.png --model qwen3.5-ocr --prompt "Output the text" \
  --base-url https://dashscope.aliyuncs.com

Expected

bl vision describe should resolve its endpoint the same way other API-key
commands do (--base-url → DASHSCOPE_BASE_URL → selected profile base_url),
or fall back to a public DashScope endpoint that actually serves VL models.

Actual

Every call without --base-url fails with HTTP 404, for every model tried
(qwen3.5-ocr, qwen-vl-ocr, qwen3-vl-plus). The same command with
--base-url https://dashscope.aliyuncs.com exits 0 and returns correct OCR text.

The configured profile's base_url is a private workspace endpoint
([REDACTED_URL]), and vision does not use that either — so neither the
profile setting nor a working default is applied.

Full output

> POST https://coding.dashscope.aliyuncs.com/compatible-mode/v1/chat/completions
> x-dashscope-source-config: {"channel":"bailian-cli","tags":{"t1":"public","t2":"bl","t3":"2.1.0"}}
< 404 Not Found

Error:       HTTP 404
Status:      HTTP 404
Exit code:   1

JSON error

{
  "error": {
    "code": 1,
    "message": "HTTP 404",
    "http_status": 404
  }
}

Already tried

• bl update to 2.1.0; skill version aligned with the CLI
• bl auth status healthy (API key + console gateway configured)
• Reproduces on every call (100%), on several models, and also on a plain
  320×90 test image with no document content
• --base-url https://dashscope.aliyuncs.com works every time

Notes

• Frequency: always
• Invoked via: terminal and agent (DeepSeek Harness)
• Impact: the error carries no hint about the endpoint, so it reads like a model
  or auth problem. Users cannot self-diagnose without --verbose, and the
  documented bl model search catalog lists these models as available. This
  breaks the entire VL/OCR surface of the CLI for anyone who does not pass
  --base-url explicitly.