UI: add W jog row (W- / W Origin / W+ / Home W) under the XYZ jog grid

Mirrors the 4-column rotary A row that appears when 2an==3, so the same
fine/small/medium/large increment selector that drives XYZ jogging now
also drives W jogging. New control-view methods:

- aux_jog_incr(sign) - PUTs aux/jog with the current jog_incr amount
  converted to mm (handles imperial display units)
- aux_move_zero() - PUTs aux/move {mm:0}, the absolute counterpart to
  aux_set_zero (which redefines the current pos as zero without moving)

Row is hidden when w.enabled is false, so users without the auxcnc
controller see no change.

src/js/control-view.js

@@ -783,6 +783,23 @@ module.exports = {
       });
     },
 
+    // Use the same fine/small/medium/large increment buttons as the XYZ
+    // jog grid. sign=+1 for W+, -1 for W-.
+    aux_jog_incr: function (sign) {
+      const amount =
+        this.jog_incr_amounts[this.display_units][this.jog_incr];
+      const delta_mm = sign * (this.metric ? amount : amount * 25.4);
+      this.aux_jog(delta_mm);
+    },
+
+    // "W Origin" - move W to 0 (absolute). Distinct from aux_set_zero,
+    // which sets the *current* position as the new zero without moving.
+    aux_move_zero: function () {
+      api.put("aux/move", { mm: 0 }).catch(function (err) {
+        console.error("W move-to-zero failed:", err);
+      });
+    },
+
     show_set_position: function (axis) {
       SvelteComponents.showDialog("SetAxisPosition", { axis });
     },

src/pug/templates/control-view.pug

@@ -107,6 +107,35 @@ script#control-view-template(type="text/x-template")
                 button(:style="getJogIncrStyle('large')", @click="jog_incr = 'large'")
                   span {{jog_incr_amounts[display_units].large}}#[span.jog-units {{metric ? 'mm' : 'in'}}]
 
+            // W axis jog row (auxcnc). Only shown when the aux controller
+            // is enabled in aux.json.
+            tr(v-if="w.enabled")
+              td(style="height:100px", align="center", colspan="1")
+                button(@click="aux_jog_incr(-1)",
+                  :disabled="!w.enabled",
+                  style="display:grid;justify-content:center;align-items:center;padding:14px;")
+                  | W-
+                  .fa.fa-arrow-down
+
+              td(style="height:100px", align="center", colspan="1")
+                button(@click="aux_move_zero()", :disabled="!w.enabled")
+                  | W
+                  br
+                  | Origin
+
+              td(style="height:100px", align="center", colspan="1")
+                button(@click="aux_jog_incr(+1)",
+                  :disabled="!w.enabled",
+                  style="display:grid;justify-content:center;align-items:center;padding:14px;")
+                  | W+
+                  .fa.fa-arrow-up
+
+              td(style="height:100px", align="center", colspan="1")
+                button(@click="aux_home()", :disabled="!w.enabled")
+                  | Home
+                  br
+                  | W
+
             tr(v-if="state['2an'] == 3")
               td(style="height:100px", align="center", colspan="1")
                 button(@click="show_probe_dialog=true")