Skip /config/dump pre-flight for md/llm endpoints in playground

[SohamKukreti]

Summary

Fixes #2222

The playground validated the Advanced Config editor via /config/dump for every endpoint, including md and llm where the panel is hidden and its result is never used. That pre-flight sends the legacy { type, code } protocol, which the server removed in the 0.8.x security fixes and rejects loudly since 0.9.3 (code is a forbidden field on untrusted requests). The fallback only rescued crawl, so md/llm (and crawl_stream) aborted with field 'code' is not permitted on CrawlerRunConfig from an untrusted request before their request was ever sent.

The fix skips the /config/dump pre-flight unless the endpoint is crawl or crawl_stream. Behavior inside the guard is unchanged.

List of files changed and why

• deploy/docker/static/playground/index.html - wrap the /config/dump pre-flight in runCrawl() with an endpoint guard so md/llm skip it; drop the now-redundant isCrawlEndpoint check inside the catch fallback.

How Has This Been Tested?

Manually verified and tested the playground
and
Drove the real playground UI with headless Chromium against a clean unclecode/crawl4ai:0.9.3 Docker container (the affected release):

• md: fit / raw / bm25+query / llm-filter, both cache modes - all succeed; only POST /md fires, no /config/dump call
• llm with a question - succeeds via GET /llm/{url}?q=...
• crawl with the default snippet - behavior unchanged: /config/dump -> fallback -> /crawl, succeeds
• crawl_stream with the default snippet - now works (streams from /crawl/stream; on stock 0.9.3 it aborted like md)
• Error paths intact: an invalid URL surfaces the server error; editor content can no longer affect md/llm

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added/updated unit tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes