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/Path/Post/scripts/linuxcnc_post.py

@@ -202,7 +202,6 @@ def export(objectslist, filename, argstring):
     gcode += linenumber() + UNITS + "\n"
 
     for obj in objectslist:
-
         # Skip inactive operations
         if not PathUtil.activeForOp(obj):
             continue
@@ -321,7 +320,6 @@ def parse(pathobj):
             out += parse(p)
         return out
     else:  # parsing simple path
-
         # groups might contain non-path things like stock.
         if not hasattr(pathobj, "Path"):
             return out
@@ -337,7 +335,6 @@ def parse(pathobj):
         #
         # for c in PathUtils.getPathWithPlacement(pathobj).Commands:
         for c in pathobj.Path.Commands:
-
             outstring = []
             command = c.Name
             outstring.append(command)
@@ -350,6 +347,34 @@ def parse(pathobj):
             if c.Name.startswith("(") and not OUTPUT_COMMENTS:  # command is a comment
                 continue
 
+            # Handle G84/G74 tapping cycles
+            if command in ("G84", "G74") and "F" in c.Parameters:
+                pitch_mm = float(c.Parameters["F"])
+                c.Parameters.pop("F")  # Remove F from output, we'll handle it
+
+                # Get spindle speed (from S param or last known value)
+                spindle_speed = None
+                if "S" in c.Parameters:
+                    spindle_speed = float(c.Parameters["S"])
+                    c.Parameters.pop("S")
+
+                # Convert pitch to inches if needed
+                if UNITS == "G20":  # imperial
+                    pitch = pitch_mm / 25.4
+                else:
+                    pitch = pitch_mm
+
+                # Calculate feed rate
+                if spindle_speed is not None:
+                    feed_rate = pitch * spindle_speed
+                    speed = Units.Quantity(feed_rate, UNIT_SPEED_FORMAT)
+                    outstring.append(
+                        "F" + format(float(speed.getValueAs(UNIT_SPEED_FORMAT)), precision_string)
+                    )
+                else:
+                    # No spindle speed found, output pitch as F
+                    outstring.append("F" + format(pitch, precision_string))
+
             # Now add the remaining parameters in order
             for param in params:
                 if param in c.Parameters:
@@ -428,8 +453,6 @@ def parse(pathobj):
                 # append the line to the final output
                 for w in outstring:
                     out += w + COMMAND_SPACE
-                # Note: Do *not* strip `out`, since that forces the allocation
-                # of a contiguous string & thus quadratic complexity.
                 out += "\n"
 
         return out