perf-tray: publish tray state on change, not on the 2s timer

The xpswatch tray lane measured ~1.9 tray signals/s at idle: refresh()
re-pushed icon (sparkline sample made every pixmap 'new'), tooltip and
menu rows every 2s, each push a NewIcon/PropertiesChanged the shell turns
into StTextureCache growth (the gnome-shell heap). Icon now publishes
only on (temp, gear, trim, badge) change, tooltip on text change with a
10s floor, rows/headers only on change.

perf-tray.py

@@ -60,6 +60,9 @@ import rig_health  # noqa: E402  (the one health.json gig-log publishes; this on
 SERVICE = "perf-tray"   # systemd --user unit controlling autostart
 END_SESSION = Path(__file__).resolve().parent / "tools" / "end_session.py"
 REFRESH_MS = 2000
+TIP_MIN_S = 10          # floor between tooltip publishes: the freq readout flaps
+                        # every tick, and each flap is a D-Bus PropertiesChanged
+                        # the appindicator extension makes the shell chew
 TRAY_WAIT_S = 120       # how long to wait for the tray host (a GNOME extension) at login
 BRIDGE_URL = "http://127.0.0.1:8773/"
 
@@ -290,6 +293,21 @@ class PerfTray:
         self.timer.start(REFRESH_MS)
         self.refresh()
 
+        # Publish-gating state (2026-11-01 tray-churn fix). The xpswatch tray lane
+        # measured this process at ~1.9 tray signals/s while idling, all of it from
+        # refresh() re-pushing the icon, tooltip and menu rows every 2 s: the
+        # sparkline gets a new sample per tick, so the pixmap is always "new", and
+        # each push is a NewIcon/PropertiesChanged the shell turns into
+        # StTextureCache growth (the gnome-shell heap, runbooks/
+        # tray-churn-and-gnome-shell-heap.md). A tray icon must change on a state
+        # change, not on a timer; the sparkline catches up on the next real one.
+        self._icon_sig = None          # (temp, gear, trim, badge) last published
+        self._last_tip = None
+        self._last_tip_t = 0.0
+        self._stat_txt = [None] * 4
+        self._health_txt = None
+        self._headers_txt = (None, None)
+
     # ------------------------------------------------------------- ending a session
     def _rig_is_up(self):
         active, _ = sc_state()
@@ -939,7 +957,10 @@ class PerfTray:
 
         gb = GB.state()
         hs = rig_health.tray_summary(rig_health.read_health())
-        self.tray.setIcon(make_icon(pkg, self.hist, gb["gear"], gb["trim"], hs["badge"]))
+        sig = (pkg, gb["gear"], gb["trim"], hs["badge"])
+        if sig != self._icon_sig:
+            self._icon_sig = sig
+            self.tray.setIcon(make_icon(pkg, self.hist, sig[1], sig[2], sig[3]))
 
         # Check the gear the FILE says, never one inferred from sysfs. The old
         # menu inferred it (perf.detect_mode reads governor/EPP/max_perf_pct), and
@@ -955,12 +976,16 @@ class PerfTray:
             act.setChecked(key == (gb["trim"] or GB.DEFAULT_TRIM))
             act.blockSignals(False)
         if GB.installed():
-            self.gear_header.setText(
+            hdr = (
                 "⚙ gear: " + (GB.label("gear", gb["gear"]) if gb["gear"]
-                              else "none engaged (ppd owns the knobs)"))
-            self.trim_header.setText(
+                              else "none engaged (ppd owns the knobs)"),
                 "🌡 trim: " + GB.label("trim", gb["trim"] or GB.DEFAULT_TRIM)
-                + ("" if gb["trim"] else " (default)"))
+                + ("" if gb["trim"] else " (default)"),
+            )
+            if hdr != self._headers_txt:
+                self._headers_txt = hdr
+                self.gear_header.setText(hdr[0])
+                self.trim_header.setText(hdr[1])
 
         # Reflect autostart state without re-triggering the toggle handler.
         self.autostart_action.blockSignals(True)
@@ -999,6 +1024,12 @@ class PerfTray:
         )
         if hs["tip"]:
             tip += "\n" + "\n".join(hs["tip"])
+        # The freq readout alone flaps every tick; push the tooltip only when the
+        # text changed AND the floor elapsed, so a live tick never publishes more
+        # than one PropertiesChanged per TIP_MIN_S.
+        if tip != self._last_tip and time.monotonic() - self._last_tip_t >= TIP_MIN_S:
+            self._last_tip = tip
+            self._last_tip_t = time.monotonic()
             self.tray.setToolTip(tip)
 
         rows = [
@@ -1007,8 +1038,12 @@ class PerfTray:
             f"freq {favg}/{fmax} MHz · fans {'/'.join(str(f) for f in fans) or 'n/a'} RPM",
             f"gpu {gpu} · thermald {td} · throttle Δ {t.throttle_delta()}",
         ]
-        for a, txt in zip(self.stat_actions, rows):
+        for a, txt, old in zip(self.stat_actions, rows, self._stat_txt):
+            if txt != old:
                 a.setText(txt)
+        self._stat_txt = rows
+        if hs["row"] != self._health_txt:
+            self._health_txt = hs["row"]
             self.health_action.setText(hs["row"])
         self.fix_driver_action.setVisible("start_driver" in hs["fixes"])
         self.fix_recorder_action.setVisible("start_recorder" in hs["fixes"])