feat: terminal aesthetic rewrite + link debug page

- Full dark terminal aesthetic (Pulse/TinkerTickets style):
  - #0a0a0a background, #00ff41 green, #ffb000 amber, #00ffff cyan
  - CRT scanline overlay, phosphor glow, ASCII corner pseudoelements
  - Bracket-notation badges [CRITICAL], monospace font throughout
  - style.css, base.html, index.html, suppressions.html all rewritten

- New Link Debug page (/links, /api/links):
  - Per-host, per-interface cards with speed/duplex/port type/auto-neg
  - Traffic bars (TX cyan, RX green) with rate labels
  - Error/drop counters, carrier change history
  - SFP/DOM optical panel: vendor, temp, voltage, bias, TX/RX power dBm bars
  - RX-TX delta shown; color-coded warn/crit thresholds
  - Auto-refresh every 60s, anchor-jump to #hostname

- LinkStatsCollector in monitor.py:
  - SSHes to each host (one connection, all ifaces batched)
  - Parses ethtool + ethtool -m (SFP DOM) output
  - Merges with Prometheus traffic/error/carrier metrics
  - Stores as link_stats in monitor_state table

- config.json: added ssh section for ethtool collection
- app.js: terminal chip style consistency (uppercase, ● bullet)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

config.json

@@ -1,4 +1,10 @@
 {
+  "ssh": {
+    "user": "root",
+    "password": "Server#980000Panda",
+    "connect_timeout": 5,
+    "timeout": 20
+  },
   "unifi": {
     "controller": "https://10.10.10.1",
     "api_key": "kyPfIsAVie3hwMD4Bc1MjAu8N7HVPIb8",