fix(browser): drop the dead --disable-javascript switch from text_mode

[talelboussetta]

Summary

text_mode appends --disable-javascript to Chromium's flags (both flag builders in browser_manager.py). Chromium has no such switch and ignores it, so text_mode has never disabled scripting: inline and external scripts run with it exactly as without it. The entry only suggests otherwise to anyone reading the flag list. JavaScript is turned off with BrowserConfig(java_script_enabled=False), which sets it on the browser context.

This removes the entry and says in the text_mode docs that JavaScript still runs. No behaviour change.

Left as is: the 0.4.1 release note says text_mode "blocks image and JavaScript resources"; it's a historical post. text_mode's route blocking covers images, fonts, media, documents and archives, not .js. deploy/docker/c4ai-code-context.md still lists the switch too; it's a generated snapshot (2025-04-21) that already predates 0.9.4's changes to the same file, so it's left for its next regeneration.

List of files changed and why

• crawl4ai/browser_manager.py: drop --disable-javascript from ManagedBrowser.build_browser_flags() and BrowserManager._build_browser_args().
• crawl4ai/async_configs.py, docs/md_v2/core/browser-crawler-config.md: one line saying JavaScript still runs under text_mode, and what turns it off.
• tests/unit/test_text_mode_flags.py (new): the switch is absent from both builders, and the switches that do take effect stay.

How Has This Been Tested?

pytest tests/unit/test_text_mode_flags.py tests/unit/test_browser_disable_features.py
5 passed        (the dead-switch test fails on develop)

The offline suites (deploy/docker/tests without the live-server test_1–test_7 scripts, tests/unit, the pool tests) show no new failures against develop.

That the switch does nothing, on an image built from develop @ 1f68e5b, which still passes it: /crawl of a page on a local test site, so CRAWL4AI_ALLOW_INTERNAL_URLS=true, whose inline and external scripts each replace a heading. The values are the headings' text in the returned HTML.

[textmode] text_mode=True             HTTP 200: #inline='INLINE-JS-RAN' #ext='EXTERNAL-JS-RAN'
[textmode] java_script_enabled=False  HTTP 200: #inline='NOJS-INLINE' #ext='NOJS-EXTERNAL'

cc @ntohidi

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

[Copilot]

Copilot review overview

🔵 Needs a closer look

Update or regenerate the Docker code-context artifact before approval.

Review effort: Lite
Findings: None

What changed in this PR

Removes the ineffective JavaScript-disabling flag from text_mode and clarifies its behavior.

Changes:

• Removes the flag from both browser argument builders.
• Updates configuration documentation.
• Adds regression tests.

File	Summary
tests/​unit/​test_text_mode_flags.py	Tests flag construction.
docs/​md_v2/​core/​browser-crawler-config.md	Clarifies JavaScript behavior.
crawl4ai/​browser_manager.py	Removes the dead flag; Docker’s code-context artifact still needs updating.
crawl4ai/​async_configs.py	Documents text_mode JavaScript behavior.

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