Center detent nubs/dimples in recessed Z engagement face

Was case_h/2 (2.75 mm); now (CAP_WALL + CAP_TOL + case_h)/2 (3.6 mm),
which is the midpoint between the recessed Z- floor and the case Z+ face.

cable_cap.scad

@@ -83,6 +83,7 @@ _cap_bore_w  = case_d - 2*CAP_WALL;                // bore Y width (fits recesse
 _cap_bore_h  = case_h + CAP_TOL;                   // bore Z height (CAP_TOL clearance on each Z face)
 _cap_gap_w   = (case_w - CAP_ENGAGE + CAP_PAD) - (win_x + ACT_W + _cham_xy); // gap between cap X- face and beveled bezel X+ end
 _detent_x    = (CAP_ENGAGE - CAP_PAD) / 2; // detent offset from cap X- face; same in cap local and case global offset
+_detent_z    = (CAP_WALL + CAP_TOL + case_h) / 2; // Z center of recessed engagement face
 // Magnetic strip recess geometry (centered on back face)
 _lip_il = MAG_L + 2 * MAG_TOL;
 _lip_iw = MAG_W + 2 * MAG_TOL;
@@ -144,7 +145,7 @@ module epd_case() {
         // Detent dimples on Y± faces — accept cap nubs when fully seated
         if (CAP_DETENT)
             for (dy = [CAP_WALL + CAP_TOL, case_d - CAP_WALL - CAP_TOL])
-                translate([case_w - CAP_ENGAGE + CAP_PAD + _detent_x, dy, case_h / 2])
+                translate([case_w - CAP_ENGAGE + CAP_PAD + _detent_x, dy, _detent_z])
                     sphere(r=DETENT_R);
 
         // Cap wall recess — step in y- face at X+ end so cap sits flush
@@ -219,7 +220,7 @@ module cable_cap() {
     // Detent nubs on Y± bore walls — snap into case dimples when fully seated
     if (CAP_DETENT)
         for (ny = [CAP_WALL, case_d - CAP_WALL])
-            translate([_detent_x, ny, case_h / 2])
+            translate([_detent_x, ny, _detent_z])
                 sphere(r=DETENT_R);
 
     // Chamfer tab: extends window bezel chamfer across the gap to the cap X- face