fix(config): make body visibility timeout configurable

[nightcityblade]

Summary

Fixes #2129.

Add CrawlerRunConfig.body_visibility_timeout, defaulting to the existing 30-second behavior, and use it for the body visibility check. This lets callers lower the ceiling for pages whose body remains hidden without changing the default crawl behavior. The value is included in config serialization and the untrusted-config allowlist.

List of files changed and why

• crawl4ai/async_configs.py - define, document, serialize, and allow the new configuration field.
• crawl4ai/async_crawler_strategy.py - pass the configured timeout to the body visibility wait.
• tests/test_config_defaults.py - cover the unchanged default and custom-value dump/load round trip.

How Has This Been Tested?

• uv run --python 3.12 --with pytest python -m pytest tests/test_config_defaults.py -q — 33 passed, 1 existing deprecation warning.
• uv run --python 3.12 --with ruff ruff check --select E9,F63,F7,F82 --ignore F821 crawl4ai/async_configs.py crawl4ai/async_crawler_strategy.py tests/test_config_defaults.py — passed. (F821 is excluded because of the existing VirtualScrollConfig forward-reference finding in async_crawler_strategy.py.)
• python3 -m compileall -q crawl4ai/async_configs.py crawl4ai/async_crawler_strategy.py tests/test_config_defaults.py — passed.
• git diff --check — passed.

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 — N/A; no complex logic was introduced.
• I have made corresponding changes to the documentation — the public configuration docstring documents the new field.
• 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

[ntohidi]

@nightcityblade Thanks — approach looks right. Default stays 30000 so nobody's existing crawls change, and I checked the plumbing: from_kwargs reads the __init__ signature so that path is covered automatically, and clone/dump/load all go through to_dict, which you updated. Allowlist entry is in the right set too.

Three things before merge:

1. Docs. docs/md_v2/api/parameters.md and docs/md_v2/complete-sdk-reference.md both document ignore_body_visibility and should get the new option too. The docstring alone isn't enough.

2. The timeout goes straight into JavaScript at async_crawler_strategy.py:324. Passing None renders > None and blows up as a RuntimeError. That's pre-existing, but this PR makes it reachable from user input, including over the Docker API now that it's allowlisted. Worth a basic check on the value.

3. The test only checks the default and a dump/load round trip. Nothing verifies the value actually reaches csp_compliant_wait — the test would still pass if the call site kept using 30000. A mock asserting the timeout that gets passed would cover the real thing.

Separate from this PR: even after it lands, the default path still spends 30 silent seconds on these pages. csp_compliant_wait returns False on timeout instead of raising, so nothing is logged and the crawl reports success. @mvletter had to profile the pipeline to find it. A debug log when that wait times out would make this option discoverable — happy to do it as a follow-up rather than expand the scope here.