docs: rewrite README with structured overview and quick start guide

Replaces the minimal project description with a comprehensive README
including a component overview table, quick start instructions, common
Ansible operations, and links to detailed documentation. Aligns with
Red Panda Approval™ standards.

ansible/caliban/xorg.conf.j2

@@ -0,0 +1,72 @@
+# XRDP Xorg configuration - Fixed 1024x768 resolution for Agent-S / UI-TARS compatibility
+# Deployed by Ansible to /etc/X11/xrdp/xorg.conf
+
+Section "ServerLayout"
+    Identifier "X11 Server"
+    Screen "Screen (xrdpdev)"
+    InputDevice "xrdpMouse" "CorePointer"
+    InputDevice "xrdpKeyboard" "CoreKeyboard"
+EndSection
+
+Section "ServerFlags"
+    # Prevent other ServerLayout sections from overriding this one
+    Option "DefaultServerLayout" "X11 Server"
+    Option "DontVTSwitch" "on"
+    Option "AutoAddDevices" "off"
+    Option "AutoAddGPU" "off"
+EndSection
+
+Section "Module"
+    Load "dbe"
+    Load "ddc"
+    Load "extmod"
+    Load "glx"
+    Load "int10"
+    Load "record"
+    Load "vbe"
+    Load "xorgxrdp"
+    Load "fb"
+EndSection
+
+Section "InputDevice"
+    Identifier "xrdpKeyboard"
+    Driver "xrdpkeyb"
+EndSection
+
+Section "InputDevice"
+    Identifier "xrdpMouse"
+    Driver "xrdpmouse"
+EndSection
+
+Section "Monitor"
+    Identifier "Monitor"
+    Option "DPMS"
+    HorizSync 30-80
+    VertRefresh 60-75
+    # Fixed resolution for Agent-S / UI-TARS compatibility
+    Modeline "1024x768" 63.50 1024 1072 1176 1328 768 771 775 798 -hsync +vsync
+    # Fallback resolutions required by xrdpdev driver
+    Modeline "800x600" 38.25 800 832 912 1024 600 603 607 624 -hsync +vsync
+    Modeline "640x480" 23.75 640 664 720 800 480 483 487 500 -hsync +vsync
+EndSection
+
+Section "Device"
+    Identifier "Video Card (xrdpdev)"
+    Driver "xrdpdev"
+    Option "DRMDevice" "/dev/dri/renderD129"
+    Option "DRI3" "1"
+    Option "DRMAllowList" "amdgpu"
+EndSection
+
+Section "Screen"
+    Identifier "Screen (xrdpdev)"
+    Device "Video Card (xrdpdev)"
+    Monitor "Monitor"
+    DefaultDepth 24
+    SubSection "Display"
+        Depth 24
+        # Fixed resolution - 1024x768 with fallbacks for xrdpdev driver
+        Modes "1024x768" "800x600" "640x480"
+        Virtual 1024 768
+    EndSubSection
+EndSection