docs(proposal): Firefox-based stealth option for browser helper

[feder-cr]

opening as draft to check interest before building the helper resolver branch.

would an optional invisible_firefox value for PLAYWRIGHT_BROWSER_TYPE be in scope, parallel to the chromium and firefox values added in PR #5250? selected via config, no change to defaults.

motivation: CloakBrowser is already wired into app/helper/browser.py as the Chromium-stealth path. private trackers and some media-info sources work better with Firefox UA, and a few have started rate-limiting CloakBrowser's Chromium UA pattern.

the backend would wrap feder-cr/invisible_playwright, which drives a patched Firefox 150 (feder-cr/invisible_firefox, MPL-2, same license as Firefox upstream, fingerprint patches at the C++ source level). drop-in compatible with the existing BrowserContext / BrowserPage / BrowserElement protocols. optional dependency.

this PR only adds a proposal doc in docs/ so the idea has somewhere concrete to land. tracking discussion: #5846

if not in scope i'll close without noise.

[gemini-code-assist]

Code Review

This pull request proposes a Firefox-based stealth option (invisible_firefox) for the browser helper to bypass rate limits and compatibility issues associated with Chromium. The review feedback points out that the proposal's maintenance section underestimates the required changes; simply updating the resolver in PlaywrightHelper.__init__ is insufficient because execution methods like action and get_page_source currently hardcode the use of cloakbrowser and must be refactored to dynamically select the browser context.

[gemini-code-assist]

In app/helper/browser.py, PlaywrightHelper currently hardcodes the use of cloakbrowser (via self.__launch_cloakbrowser_context) in both action and get_page_source methods, completely ignoring self.browser_type.

Therefore, simply adding a resolver branch in PlaywrightHelper.__init__ will not be sufficient. The execution methods (action and get_page_source) will also need to be refactored to dynamically select and launch the appropriate browser context (e.g., standard Playwright, CloakBrowser, or invisible_playwright) based on self.browser_type or self.__browser_emulation().

Please update the proposal to reflect these required changes in the browser helper execution flow.

Suggested change

	Issues against the backend route to feder-cr/invisible_playwright. Only ask of this repo would be the resolver branch in `PlaywrightHelper.__init__` plus a config docstring update.
	Issues against the backend route to feder-cr/invisible_playwright. The implementation would require updating the resolver in PlaywrightHelper and refactoring its execution methods (action and get_page_source) to dynamically route to the correct browser context launcher based on self.browser_type, along with a config docstring update.