feat(hamlog): the settings panel, the key check, and a row-colour channel

HAMLOG.online is now reachable: Settings → External services → HAMLOG.ONLINE
takes the API key, the auto-upload switch and the timing, exactly like the six
services beside it, and a link opens the page where the key is issued.

The button next to it checks the KEY, not the connection. HAMLOG answers
KEYSTATUS with the callsign the key belongs to — something no other service
here offers — so the result reads "Key is valid — account F4BPO" rather than a
green tick. A key pasted from a club account or a second station is visible at
once, which is precisely the mistake a tick would have hidden.

No on-close timing, for the same reason as Cloudlog: there is no per-QSO upload
column to select a backlog from at shutdown, so the option would have done
nothing. Immediate or delayed, and a stored on_close falls back to immediate
rather than silently uploading nothing.

The appearance rules gain a HAMLOG.online channel too, so a row can be coloured
"confirmed" on that alone. It reads the ADIF extras — the standard names a field
for hamlog.EU and none for hamlog.ONLINE — using the same keys the award engine
reads, so the two can never disagree about what a confirmation is. "To send"
skips it: a QSO is either uploaded or not, there is no card to be owed.

frontend/src/components/AppearancePanel.tsx

@@ -29,9 +29,9 @@ const LABELS: Record<string, string> = {
 
 // The channels a rule can be scoped to. "worked" is the catch-all — it means
 // nothing on ANY channel — so narrowing it would say nothing.
-const CHANNELS = ['qsl', 'lotw', 'eqsl', 'qrz'] as const;
+const CHANNELS = ['qsl', 'lotw', 'eqsl', 'qrz', 'hamlog'] as const;
 const CHANNEL_LABELS: Record<string, string> = {
-  qsl: 'appr.chQsl', lotw: 'LoTW', eqsl: 'eQSL', qrz: 'QRZ.com',
+  qsl: 'appr.chQsl', lotw: 'LoTW', eqsl: 'eQSL', qrz: 'QRZ.com', hamlog: 'HAMLOG.online',
 };
 
 // MatrixColorsSection recolours the band/mode matrix — the PH/CW/DIG grid in the