cherry-pick #1: initial Kindred branding + assembly joint fix

Cherry-picked 316d4f4b52 with conflict resolution:
- CMakeLists.txt: merged Kindred version vars with upstream 1.2.0-dev base
- src/Main/*.cpp: applied Kindred branding (banner, copyright, license)
- Resolved add/add conflicts for files already copied in Phase 1
- Includes assembly joint flip overconstrain fix

src/Gui/PreferencePacks/CMakeLists.txt

@@ -3,6 +3,7 @@ SET(PreferencePacks_Files
 )
 
 SET(PreferencePacks_Directories
+        "KindredCreate"
         "FreeCAD Classic"
         "Dark behave"
         "FreeCAD Light"

src/Gui/PreferencePacks/package.xml

@@ -1,12 +1,23 @@
 <?xml version="1.0" encoding="UTF-8" standalone="no" ?>
 <package format="1">
   <name>Built-In Preference Packs</name>
-  <description>Preference Packs included with the FreeCAD distribution</description>
+  <description>Preference Packs included with the Kindred Create distribution</description>
   <version>1.0.0</version>
-  <maintainer email="email@FreeCAD.org">MisterMaker</maintainer>
+  <maintainer email="support@kindredsystems.net">Kindred Systems LLC</maintainer>
   <license file="../../LICENSE">LGPL2</license>
-  <url type="repository">https://github.com/FreeCAD/FreeCAD</url>
+  <url type="repository">https://github.com/kindredsystems/create</url>
   <content>
+    <preferencepack>
+      <name>KindredCreate</name>
+      <type>Theme</type>
+      <description>The default Kindred Create theme based on Catppuccin Mocha - a soothing dark color palette with carefully chosen colors for optimal readability.</description>
+      <version>1.0.0</version>
+      <tag>built-in</tag>
+      <tag>default</tag>
+      <tag>dark</tag>
+      <tag>catppuccin</tag>
+      <tag>mocha</tag>
+    </preferencepack>
     <preferencepack>
       <name>FreeCAD Classic</name>
       <type>Theme</type>
@@ -17,8 +28,8 @@
       <tag>no stylesheet</tag>
       <tag>classic theme</tag>
     </preferencepack>
-	<preferencepack>
-	  <name>FreeCAD Light</name>
+    <preferencepack>
+      <name>FreeCAD Light</name>
       <type>Theme</type>
       <description>Applies a basic light theme.</description>
       <version>1.0.0</version>
@@ -26,8 +37,8 @@
       <tag>background</tag>
       <tag>light</tag>
     </preferencepack>
-	<preferencepack>
-	  <name>FreeCAD Dark</name>
+    <preferencepack>
+      <name>FreeCAD Dark</name>
       <type>Theme</type>
       <description>Applies a basic dark theme.</description>
       <version>1.0.0</version>