INI import: strip greeting quotes; add gsheet reference

Strip a surrounding pair of double quotes from the [Plasma] Greeting on
import (the gsheet "INI_V2" output writes Greeting="..."), and add the
master button-layout spreadsheet that documents the RIO.ini format and the
16-bit map-word encoding. Test covers the real sheet output (modifier-stacked
words, keypad VK words, RIO command words) round-tripping verbatim.

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

src/RioJoy.Core/Profiles/RioIniImporter.cs

@@ -21,7 +21,7 @@ public static class RioIniImporter
         var profile = new RioProfile
         {
             Name = name,
-            PlasmaGreeting = ini.GetString("Plasma", "Greeting"),
+            PlasmaGreeting = StripQuotes(ini.GetString("Plasma", "Greeting")),
             WallpaperPath = ini.GetString("Desktop", "File"),
             Calibration = new AxisCalibrationConfig
             {
@@ -48,6 +48,16 @@ public static class RioIniImporter
         return profile;
     }
 
+    // The gsheet writes the greeting as a quoted string (e.g. Greeting="Hello,");
+    // strip a single pair of surrounding double quotes so it displays cleanly.
+    private static string? StripQuotes(string? value)
+    {
+        if (value is null)
+            return null;
+        string v = value.Trim();
+        return v.Length >= 2 && v[0] == '"' && v[^1] == '"' ? v[1..^1] : v;
+    }
+
     // Keys look like "RIO00".."RIO6F": "RIO" + a hex address into the iRIO table.
     private static bool TryParseButtonAddress(string key, out int address)
     {