chore: update MeshCore URLs to use new site (#1445)

# Summary
The main MeshCore website is https://meshcore.io. Reasons for the new
website are listed here: https://blog.meshcore.io/2026/04/23/the-split

# Changes
Any occurrence of `meshcore.co.uk` was replaced with `meshcore.io`. No
logic was changed, only updated strings.

Co-authored-by: hrtndev <hrtndev@users.noreply.github.com>

cmd/server/routes.go

@@ -490,7 +490,7 @@ func (s *Server) handleConfigTheme(w http.ResponseWriter, r *http.Request) {
 		"heroTitle":    "CoreScope",
 		"heroSubtitle": "Real-time MeshCore LoRa mesh network analyzer",
 		"steps": []interface{}{
-			map[string]interface{}{"emoji": "🔵", "title": "Connect via Bluetooth", "description": "Flash **BLE companion** firmware from [MeshCore Flasher](https://flasher.meshcore.co.uk/).\n- Screenless devices: default PIN `123456`\n- Screen devices: random PIN shown on display\n- If pairing fails: forget device, reboot, re-pair"},
+			map[string]interface{}{"emoji": "🔵", "title": "Connect via Bluetooth", "description": "Flash **BLE companion** firmware from [MeshCore Flasher](https://flasher.meshcore.io/).\n- Screenless devices: default PIN `123456`\n- Screen devices: random PIN shown on display\n- If pairing fails: forget device, reboot, re-pair"},
 			map[string]interface{}{"emoji": "📻", "title": "Set the right frequency preset", "description": "**US Recommended:**\n`910.525 MHz · BW 62.5 kHz · SF 7 · CR 5`\nSelect **\"US Recommended\"** in the app or flasher."},
 			map[string]interface{}{"emoji": "📡", "title": "Advertise yourself", "description": "Tap the signal icon → **Flood** to broadcast your node to the mesh. Companions only advert when you trigger it manually."},
 			map[string]interface{}{"emoji": "🔁", "title": "Check \"Heard N repeats\"", "description": "- **\"Sent\"** = transmitted, no confirmation\n- **\"Heard 0 repeats\"** = no repeater picked it up\n- **\"Heard 1+ repeats\"** = you're on the mesh!"},

public/customize-v2.js

@@ -10,7 +10,7 @@
     heroTitle: 'CoreScope',
     heroSubtitle: 'Real-time MeshCore LoRa mesh network analyzer',
     steps: [
-      { emoji: '🔵', title: 'Connect via Bluetooth', description: 'Flash **BLE companion** firmware from [MeshCore Flasher](https://flasher.meshcore.co.uk/).\n- Screenless devices: default PIN `123456`\n- Screen devices: random PIN shown on display\n- If pairing fails: forget device, reboot, re-pair' },
+      { emoji: '🔵', title: 'Connect via Bluetooth', description: 'Flash **BLE companion** firmware from [MeshCore Flasher](https://flasher.meshcore.io/).\n- Screenless devices: default PIN `123456`\n- Screen devices: random PIN shown on display\n- If pairing fails: forget device, reboot, re-pair' },
       { emoji: '📻', title: 'Set the right frequency preset', description: '**US Recommended:**\n`910.525 MHz · BW 62.5 kHz · SF 7 · CR 5`\nSelect **"US Recommended"** in the app or flasher.' },
       { emoji: '📡', title: 'Advertise yourself', description: 'Tap the signal icon → **Flood** to broadcast your node to the mesh. Companions only advert when you trigger it manually.' },
       { emoji: '🔁', title: 'Check "Heard N repeats"', description: '- **"Sent"** = transmitted, no confirmation\n- **"Heard 0 repeats"** = no repeater picked it up\n- **"Heard 1+ repeats"** = you\'re on the mesh!' }

public/home.js

@@ -552,7 +552,7 @@
         { q: '💬 First: Join the Bay Area MeshCore Discord',
           a: '<p>The community Discord is the best place to get help and find local mesh enthusiasts.</p><p><a href="https://discord.gg/q59JzsYTst" target="_blank" rel="noopener" style="color:var(--accent);font-weight:600">Join the Discord ↗</a></p><p>Start with <strong>#intro-to-meshcore</strong> — it has detailed setup instructions.</p>' },
         { q: '🔵 Step 1: Connect via Bluetooth',
-          a: '<p>Flash <strong>BLE companion</strong> firmware from <a href="https://flasher.meshcore.co.uk/" target="_blank" rel="noopener" style="color:var(--accent)">MeshCore Flasher</a>.</p><ul><li>Screenless devices: default PIN <code>123456</code></li><li>Screen devices: random PIN shown on display</li><li>If pairing fails: forget device, reboot, re-pair</li></ul>' },
+          a: '<p>Flash <strong>BLE companion</strong> firmware from <a href="https://flasher.meshcore.io/" target="_blank" rel="noopener" style="color:var(--accent)">MeshCore Flasher</a>.</p><ul><li>Screenless devices: default PIN <code>123456</code></li><li>Screen devices: random PIN shown on display</li><li>If pairing fails: forget device, reboot, re-pair</li></ul>' },
         { q: '📻 Step 2: Set the right frequency preset',
           a: '<p><strong>US Recommended:</strong></p><div style="margin:8px 0;padding:8px 12px;background:var(--surface-1);border-radius:6px;font-family:var(--mono);font-size:.85rem">910.525 MHz · BW 62.5 kHz · SF 7 · CR 5</div><p>Select <strong>"US Recommended"</strong> in the app or flasher.</p>' },
         { q: '📡 Step 3: Advertise yourself',

public/roles.js

@@ -428,7 +428,7 @@
 
   // ─── External URLs ───
   window.EXTERNAL_URLS = {
-    flasher: 'https://flasher.meshcore.co.uk/'
+    flasher: 'https://flasher.meshcore.io/'
   };
 
   // ─── Fetch server overrides ───