onu detail polish + clickable OLT detail modal

- Fix alarm card overflow: alarm rows stack (severity+text on one line that
  wraps, meta below) instead of squeezing the text to ~0 width next to the
  nowrap meta — which had made long alarm text render one char per line in
  narrow columns. Also min-width:0 on cards/kv so long IPv6/descr strings
  don't blow out the grid track.
- Combine Parent OLT + Upstream switch into one "Parent OLT & uplink" card.
- ONU list/search de-compacted: add equipment/version + PON-mode filters;
  two-line rows (serial+status, then equipment · version · last-seen).
- UNI card labels the speed as configured ("cfg Auto/Auto"); negotiated
  speed isn't in the payloads — link up/down still comes from LAN-LOS.

Clickable parent OLT -> OLT detail modal (showOltModal):
- new src/oltdetail.js (pure, shared; reuses summarizeAlarms) + getOltState
  / getOltAlarms client methods + api:getOltDetail (main + web + bridges).
- shows identity, traffic + util, ASIC temperature, ONU counts, laser,
  alarms, upstream switch; plus a connected-ONU list with per-ONU
  FEC/optical built from the loaded fleet (filtered by _status.oltMac),
  each row clickable back into that ONU's detail.

Docs: CLAUDE.md §17 + IPC table.

Verified: node --check; oltdetail.js unit-tested 9/9 (fw active-bank,
traffic down=TX/up=RX, util, ASIC temp, ONU counts, laser, LLDP, alarms);
rendered the OLT modal + richer list offscreen and confirmed the alarm-text
wrap fix (alarm head ~1-2 lines, not vertical).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

preload.js

@@ -17,6 +17,7 @@ contextBridge.exposeInMainWorld('api', {
   getOnuConfig: (opts) => call('api:getOnuConfig', opts),
   getOnuCpe: (opts) => call('api:getOnuCpe', opts),
   getOnuDetail: (opts) => call('api:getOnuDetail', opts),
+  getOltDetail: (opts) => call('api:getOltDetail', opts),
   listOnuFirmware: () => call('api:listOnuFirmware'),
   uploadFirmware: () => call('api:uploadFirmware'),