feat: replace TCP sockets with WebSocket, MPLogger with OTel, StorageController as thread

[vringar]

Summary

Major architectural refactoring of OpenWPM's internal communication and infrastructure:

• WebSocket: Replace raw TCP socket IPC between Extension and Python with a single bidirectional WebSocket connection per browser (removes dependency on privileged browser.sockets experiment API)
• StorageController: Convert from a separate process (with async TCP server) to a thread using multiprocess.Queue for data flow
• Telemetry: Replace MPLogger with OpenTelemetry tracing + standard Python logging (structured traces, per-browser context, optional OTLP export)
• Command API: Introduce ExtensionSocket Protocol type for backward-compatible BaseCommand.execute() signature
• Unicode fix: Remove UTF-8 byte encoding in escapeString (was needed for old binary socket protocol, breaks JSON/WebSocket)

New files

• openwpm/telemetry.py — OTel TracerProvider + Python logging setup
• openwpm/websocket_bridge.py — WebSocketBridge (asyncio WS server in thread) + ExtensionSocketAdapter
• Extension/src/websocket-client.ts — Browser-side WebSocket client

Key design decisions

• BrowserManager stays as a separate process (crash isolation for robustness at scale)
• Data flows: Extension → WebSocket → BrowserManager process → multiprocess.Queue → StorageController thread
• Public config API (BrowserParams, ManagerParams, CommandSequence, BaseCommand) unchanged

Test plan

• All 110 tests passing (16 simple_commands, 17 HTTP, 6 JS instrument, 21 profile, 5 task_manager, 10 storage, + others)
• mypy clean (44 files, 0 errors)
• Extension lint clean (0 errors)
• POST data Unicode encoding verified (was broken, fixed via escapeString change)

[codecov]

Codecov Report

❌ Patch coverage is 76.92308% with 66 lines in your changes missing coverage. Please review.
✅ Project coverage is 57.64%. Comparing base (58218c7) to head (f3d75f8).

Files with missing lines	Patch %	Lines
openwpm/telemetry.py	61.53%	35 Missing ⚠️
openwpm/websocket_bridge.py	85.41%	14 Missing ⚠️
openwpm/storage/storage_controller.py	85.00%	9 Missing ⚠️
test/test_mp_logger.py	0.00%	3 Missing ⚠️
openwpm/browser_manager.py	89.47%	2 Missing ⚠️
test/test_custom_function_command.py	50.00%	2 Missing ⚠️
test/test_xvfb_browser.py	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1144      +/-   ##
==========================================
- Coverage   62.16%   57.64%   -4.52%     
==========================================
  Files          40       42       +2     
  Lines        3898     3978      +80     
==========================================
- Hits         2423     2293     -130     
- Misses       1475     1685     +210     

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