add TOOL_TYPE offset to tcp_pose for vacuum and gripper

Apply Z-axis tool offset when publishing tcp_pose so the output
reflects the actual tool tip. Adds TOOL_TYPE (none/vacuum/gripper)
and TOOL_OFFSET_MM env vars with standard Lite6 accessory presets.
Bump version to 0.1.2.

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "dora-ulite6"
-version = "0.1.1"
+version = "0.1.2"
 license = "MIT"
 authors = [
   { name = "Dora" }