Log tabs with a daemon I/O view, and Playwright UI tests

The log view splits into All / Daemon I/O / Scans / HTTP. Daemon I/O is
the control protocol itself, logged where every command funnels through
so it covers socket clients, the CLI and the web UI alike. stderr and the
in-app buffer now have separate filters, so the UI can keep debug detail
the terminal should not carry.

Playwright drives a real browser against a daemon on fixture feeds. Eight
tests, each mapping to a bug that reached a user -- the Rust tests and the
stub-DOM smoke test cannot see a wrong selector or a dead handler.

It immediately found one: OPML folders rendered expanded by default,
because the code stored closed groups, so any folder never toggled counted
as open.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AdXho5tTkjFLeUXKbEjKBh

README.md

@@ -163,11 +163,32 @@ Put it behind a reverse proxy with TLS if that matters to you.
 
 ## Log view
 
-The **Log** button in the sidebar shows the running daemon's output live: feed scans, downloads,
+The **Log** button in the sidebar shows the running daemon's output live, in four tabs:
+**Daemon I/O** is the control protocol itself — every command in and every event out, as JSON;
+**Scans** is feed and download activity; **HTTP** is web requests; **All** is everything: feed scans, downloads,
 torrent activity and every HTTP request, with level and text filters and a copy button. It reads a
 2000-line ring buffer held inside the process (`/api/logs`), not a file — so it works the same under
-Docker, where logs go to stdout and there is no file to tail. `IPX_LOG=ipx=debug` adds detail;
-`IPX_LOG=ipx=info,librqbit=info` shows what torrents are doing.
+Docker, where logs go to stdout and there is no file to tail. The buffer keeps `debug` even when the terminal does not, so protocol traffic and routine
+skips are there without making stderr unreadable — `IPX_UI_LOG` changes what it captures and
+`IPX_LOG` what reaches stderr.
+
+## Tests
+
+```sh
+cargo test              # the server: parsing, filters, retention, schedules, SQL
+node tests/page-smoke.js  # the page script loads without throwing
+npx playwright test     # a real browser against a real daemon
+```
+
+The Rust tests cover the server and the smoke test catches a script that fails to load, but neither
+can see a wrong selector, a handler that runs and does nothing, or a page that renders empty — which
+is what has actually slipped through. The Playwright suite drives a headless browser against a
+daemon started on fixture feeds, and each test maps to a bug that reached a user: the page rendering
+empty, a dead theme toggle, settings not persisting, episode metadata, filter tabs, the feed URL
+field and its copy button, the log tabs, and OPML folders.
+
+`npm install` gets the test runner; the browser itself comes from
+`npx playwright install --with-deps chromium` (in `install.sh`).
 
 ## Docker