CAM: Convert tapping operation to experimental feature, Add tap pitch support, improve tapping logic, and update toolbit schema and legacy linuxcnc post

CAM/App/PathSegmentWalker.cpp
- Add G74 to drill/tap/bore G-code recognition for tapping cycles

CAM/InitGui.py
- Move CAM_Tapping command behind experimental feature flag
- Only group drilling/tapping commands if both are enabled

CAM/Path/Base/Generator/tapping.py
- Add pitch and spindle_speed parameters to tapping.generate
- Output S (spindle speed) and F (pitch) in generated G-code

CAM/Path/Op/Tapping.py
- Require Pitch property for tap tools and SpindleSpeed for tool controllers
- Pass pitch and spindle speed to tapping.generate
- Use SpindleDirection to determine right/left hand tap

CAM/Path/Post/scripts/linuxcnc_post.py
- Handle G84/G74 tapping cycles: convert pitch and spindle speed to feed rate
- Remove F and S from output and recalculate F as needed

CAM/Path/Tool/shape/models/tap.py
- Add Pitch property to ToolBitShapeTap schema
- CAM/Path/Tool/toolbit/models/tap.py
- Show pitch and rotation in tap tool summary
- Use is_imperial_pitch to format pitch as TPI or mm

CAM/Path/Tool/toolbit/util.py
- Add is_imperial_pitch utility to classify pitch as imperial or metric

CAM/Tools/Bit/375-16_Tap.fctb
- Remove unused parameters (Coating, Rotation, TPI, Type)
- Keep only relevant tap parameters for new schema

src/Mod/CAM/App/PathSegmentWalker.cpp

@@ -313,8 +313,9 @@ void PathSegmentWalker::walk(PathSegmentVisitor& cb, const Base::Vector3d& start
             // relative mode
             absolutecenter = false;
         }
-        else if ((name == "G73") || (name == "G81") || (name == "G82") || (name == "G83")
-                 || (name == "G84") || (name == "G85") || (name == "G86") || (name == "G89")) {
+        else if ((name == "G73") || (name == "G74") || (name == "G81") || (name == "G82")
+                 || (name == "G83") || (name == "G84") || (name == "G85") || (name == "G86")
+                 || (name == "G89")) {
             // drill,tap,bore
             double r = 0;
             if (cmd.has("R")) {