fix: Rebrand project from PiPedal to OP-Pedal

Updated branding across the project:
- CMakeLists.txt: project name, description, homepage, display version
- src/PiPedalVersion.cpp: server name string
- debian/control: package name, source, homepage, description
- vite/package.json: package name
- vite/index.html: title, meta description
- vite/public/manifest.json: name, short_name, description, URLs
- UI files: AboutDialog, AppThemed, MainPage, SettingsDialog,
  UpdateDialog, WifiConfigDialog, WifiConfigSettings,
  WifiDirectConfigSettings, Tone3000Downloader, Tone3000HelpDialog,
  WindowScale

Preserved upstream copyright/attribution and legal references.

vite/public/manifest.json

@@ -1,14 +1,14 @@
 {
     "manifest_version": 3,
-    "short_name": "PiPedal",
-    "name": "PiPedal",
+    "short_name": "OP-Pedal",
+    "name": "OP-Pedal",
     "author": "Robin E.R. Davies",
-    "description": "A web-based client for the PiPedal guitar effects processor.",
+    "description": "A web-based client for the OP-Pedal guitar effects processor.",
     "developer": {
         "name": "Robin E.R. Davies",
-        "url": "https://rerdavies.github.io"
+        "url": "https://ourpad.casa/op-pedal"
     },
-    "homepage_url": "https://rerdavies.github.io/pipedal",
+    "homepage_url": "https://ourpad.casa/op-pedal",
     "icons": [
         {
             "src": "favicon.ico",