Macros: fix wrong-file race, suppress HOOK message popups, preprocess at load

Three fixes for macro/W-axis interaction:

1. run_macro raced the file selection. The frontend mutated
   state.selected client-side and immediately fired api.put('start').
   Selection on the server is a side effect of GET /api/file/<name>
   (FileHandler.get calls state.select_file). The GET request was
   often still in flight when start ran, so mach.start() executed
   whichever file was selected last - pressing W Down would re-run
   W Up. Now run_macro awaits the file fetch before starting.

2. (MSG,HOOK:aux:N) lines, used as the IPC channel between the
   W-axis preprocessor and the Hooks system, were leaking to the
   user as message popups (because the planner forwards every
   (MSG,...) comment to state.messages). Filter HOOK: messages in
   Planner._add_message: still pushed through state.messages so
   Hooks._on_state_change can dispatch them, but immediately
   acked so the UI doesn't render them.

3. AuxPreprocessor only ran at upload time (FileHandler.put_ok and
   Mach.mdi). Files written via scp, restored from a config backup,
   or hand-edited still contained raw W tokens that the planner
   couldn't parse. Run preprocess_file in Planner.load() too. It's
   idempotent (no-op when no W tokens remain) so re-loading a
   already-rewritten file is free.

src/js/program-mixin.js

@@ -564,23 +564,32 @@ module.exports = {
     override_feed:  function () { api.put(`override/feed/${this.feed_override}`); },
     override_speed: function () { api.put(`override/speed/${this.speed_override}`); },
 
-    run_macro: function (id) {
+    run_macro: async function (id) {
       if (this.state.macros[id].file_name == "default") {
         this.showNoGcodeMessage = true;
-      } else {
-        if (this.state.macros[id].file_name != this.state.selected) {
-          this.state.selected = this.state.macros[id].file_name;
+        return;
       }
+      const file_name = this.state.macros[id].file_name;
       try {
+        // Selecting a file on the server is a side effect of
+        // GET /api/file/<name>. The macro button used to mutate
+        // state.selected client-side and immediately call start, which
+        // raced the file fetch: if the server hadn't seen the new
+        // selection yet, mach.start() ran whichever file was selected
+        // last. Do it explicitly and await so start always sees the
+        // right file.
+        if (file_name != this.state.selected) {
+          this.state.selected = file_name;
+          await api.get(`file/${encodeURIComponent(file_name)}`);
+        }
         this.load();
         if (this.state.macros[id].alert == true) {
           this.macrosLoading = true;
         } else {
-            setImmediate(() => this.start_pause());
+          await this.start_pause();
         }
       } catch (error) {
-          console.warn("Error running program: ", error);
-        }
+        console.warn("Error running macro: ", error);
       }
     },
   },

src/py/bbctrl/Planner.py

@@ -196,12 +196,29 @@ class Planner():
 
 
     def _add_message(self, text):
-        self.ctrl.state.add_message(text)
-
+        # HOOK:<event>:<data> messages are an internal IPC channel
+        # between the gcode preprocessor and Hooks; they should not
+        # surface as user-visible message popups. Hooks._on_state_change
+        # will still see them via the messages list before we filter.
         line = self.ctrl.state.get('line', 0)
         if 0 <= line: where = '%s:%d' % (self.where, line)
         else: where = self.where
 
+        if isinstance(text, str) and text.startswith('HOOK:'):
+            # Push it through state.messages so Hooks._on_state_change
+            # can see and dispatch it, then immediately ack it so the UI
+            # doesn't render a popup.
+            self.ctrl.state.add_message(text)
+            try:
+                msgs = self.ctrl.state.get('messages', []) or []
+                if msgs:
+                    self.ctrl.state.ack_message(msgs[-1].get('id', -1))
+            except Exception:
+                pass
+            self.log.info('HOOK msg: %s' % text, where = where)
+            return
+
+        self.ctrl.state.add_message(text)
         self.log.message(text, where = where)
 
 
@@ -369,6 +386,17 @@ class Planner():
         self.where = path
         path = self.ctrl.get_path('upload', path)
         self.log.info('GCode:' + path)
+        # Make sure W-axis tokens are rewritten before the planner sees
+        # the file. preprocess_file is a no-op for files without W and
+        # for files already rewritten (no W tokens remain after the
+        # first pass), so this is safe to run on every load.
+        try:
+            from bbctrl.AuxPreprocessor import preprocess_file
+            if preprocess_file(path, log = self.log):
+                self.log.info('Rewrote W-axis tokens in %s' % path)
+        except Exception:
+            self.log.exception('W-axis preprocess at load failed; '
+                               'attempting to load file unchanged')
         self._sync_position()
         self.planner.load(path, self.get_config(False, True))
         self.reset_times()