Add HarRecordingWatchdog for HTTPS HAR capture

[kalil0321]

#3063

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Summary by cubic

Add HarRecordingWatchdog to capture HTTPS network traffic via CDP and write a HAR 1.2 file on browser shutdown. Auto-attaches when browser_profile.record_har_path is set and supports configurable content storage and capture modes.

• New Features

  • Records HTTPS requests/responses (bodies and request postData) and saves to browser_profile.record_har_path on stop.
  • Supports record_har_content: embed (text or base64), attach (sidecar dir: <har_stem>_har_parts), or omit.
  • Supports record_har_mode: full or minimal (main doc + same-origin subresources).
  • Adds browser/version metadata, page refs, and DOMContentLoaded/load timings.

• Migration

  • Set browser_profile.record_har_path to enable.
  • Optional: configure record_har_content (embed|attach|omit) and record_har_mode (full|minimal).

^{Written for commit 6dbdaab6b163824cc7365d567abd3ead097f03fe. Summary will update automatically on new commits.}

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[!NOTE] Introduce HarRecordingWatchdog to capture HTTPS traffic via CDP and write a HAR 1.2 file on shutdown, configurable for content storage and capture scope, and auto-attached to sessions.

• Watchdogs:
  • HarRecordingWatchdog (new):
    • Captures HTTPS requests/responses via CDP (Network, Page) and writes HAR 1.2 on BrowserStopEvent.
    • Configurable: record_har_content (embed/attach/omit) with sidecar dir for attach; record_har_mode (full/minimal).
    • Records response bodies, headers, sizes, compression, timings; includes pages with titles and DOMContentLoaded/load metrics; embeds browser metadata.
• Session Integration:
  • Import, initialize, and attach HarRecordingWatchdog in BrowserSession.attach_all_watchdogs() (auto-enabled when record_har_path is set).

^{Written by Cursor Bugbot for commit b53a593d334e048eabe758e9727106763089e4ec. Configure here.}

[kalil0321]

TODO: missing req & resp body size + resp content; pages: title, strateddt, timings;

[mertunsall]

Hi @kalil0321 - what's the purpose of this?

[mertunsall]

also can we disable it by default please?

[kalil0321]

Hi @mertunsall, thanks a lot for merging the PRs :)! This PR records the HAR to capture network activity. I will link the related issue ASAP and disable it.

[mertunsall]

Hi @kalil0321 , of course sorry for being late.

I like this - let's just disable this by default.