fix: pad armed receive on group, lua guards

Move /armed/<name> receive msg from arm BUTTON to parent GROUP so
pad.lua onReceiveOSC fires on the node that owns the message (FIX 1).
Remove feedback.lua from master RMS fader; native receive already
drives the VU, onFrame decay was pure downside (FIX 3).
Add Lua 5.1/LuaJIT compat shim for table.unpack in melody_faders
(FIX 2). Document deferred sequencer playhead in README (FIX 4).
Regression test: 16 pad GROUPs carry /armed/* receive; 21 tests pass.
Rebuild dist/av-live-control.tosc.

touchosc/README.md

@@ -93,3 +93,7 @@ Feedback (SC → surface, port 9000, all created by `touchosc_feedback.scd`):
   voices to bus 0, so per-voice live levels are not producible without
   re-routing the audio. The master RMS VU + beat + per-pad armed reflection
   cover the live-feedback need.
+- **Sequencer playhead / step-index highlight** (spec §2/§4/§7) is
+  **deferred**: the data-only engine does not emit a step index over OSC, so
+  adding column-highlight requires a new SC step-emit plus a layout
+  column-highlight receiver. Not built in this pass.

touchosc/gen/layout.py

@@ -82,7 +82,6 @@ def _pad_cell(name, x, y, w, h):
         [s.prop("name", name, "s"), s.frame(0, 0, w - 20, btn_h)],
         messages=[
             s.osc("/launch", [s.const(name), s.vali()]),
-            s.osc(f"/armed/{name}", [s.val()], send=0, receive=1, feedback=1),
         ],
     )
     vol_fader = s.node(
@@ -99,6 +98,7 @@ def _pad_cell(name, x, y, w, h):
             s.script(_lua("pad.lua")),
         ],
         children=[arm_btn, vol_fader, name_label],
+        messages=[s.osc(f"/armed/{name}", [s.val()], send=0, receive=1, feedback=1)],
     )
 
 
@@ -126,8 +126,7 @@ def live_page():
     # Master VU fader (receive-only /sync/rms)
     ch.append(s.node(
         "FADER",
-        [s.prop("name", "rms", "s"), s.frame(490, 8, 40, 72),
-         s.script(_lua("feedback.lua"))],
+        [s.prop("name", "rms", "s"), s.frame(490, 8, 40, 72)],
         messages=[s.osc("/sync/rms", [s.val()], send=0, receive=1, feedback=1)],
     ))
 

touchosc/gen/lua/melody_faders.lua

@@ -2,6 +2,7 @@
 -- On value change: read all 8 step faders (m0..m7) -> /seq/melody/set.
 -- API verified on GrosMac at fidelity gate.
 local LO, HI = -7, 14
+local unpack = table.unpack or unpack  -- Lua 5.1 / LuaJIT compat
 
 function onValueChanged(key)
   if key ~= "x" then return end
@@ -12,5 +13,5 @@ function onValueChanged(key)
     local fx = (f and f.values and f.values.x) or 0
     degs[i] = math.floor(LO + (HI - LO) * fx + 0.5)
   end
-  sendOSC("/seq/melody/set", table.unpack(degs))
+  sendOSC("/seq/melody/set", unpack(degs))
 end

touchosc/tests/test_layout.py

@@ -247,3 +247,53 @@ def test_seq_page_no_sync_amp():
     page = layout.seq_page()
     addrs = _addrs(page)
     assert "/sync/amp" not in addrs, "/sync/amp found — per-voice VU was supposed to be omitted"
+
+
+# ---------------------------------------------------------------------------
+# Pad armed receive on GROUP — FIX 1 regression guard
+# ---------------------------------------------------------------------------
+
+def test_live_page_pad_groups_carry_armed_receive():
+    """Each pad GROUP (carrying pad.lua) must have the /armed/<name> receive
+    message on itself — not only on the child arm BUTTON.  pad.lua fires via
+    onReceiveOSC on the node that owns the matching receive message; if the
+    message lives only on the child BUTTON, the GROUP script never fires and
+    armed-state color reflection is dead."""
+    page = layout.live_page()
+
+    # Collect GROUP nodes that carry a script property (= pad GROUPs with pad.lua).
+    # The top-level LIVE GROUP has no script, so this selects exactly the 16 pads.
+    pad_groups = []
+    for grp in page.findall(".//node[@type='GROUP']"):
+        for prop_el in grp.findall("properties/property"):
+            key_el = prop_el.find("key")
+            if key_el is not None and key_el.text == "script":
+                pad_groups.append(grp)
+                break
+
+    assert len(pad_groups) == 16, (
+        f"expected 16 pad GROUPs with a script property, got {len(pad_groups)}"
+    )
+
+    for grp in pad_groups:
+        # Resolve the pad name from its name property for a readable failure msg.
+        grp_name = "?"
+        for prop_el in grp.findall("properties/property"):
+            k = prop_el.find("key")
+            if k is not None and k.text == "name":
+                v = prop_el.find("value")
+                grp_name = v.text if v is not None else "?"
+                break
+
+        # The GROUP's direct <messages> block (not descendants) must contain
+        # exactly one osc element with receive="1" whose path starts /armed/.
+        armed_msgs = [
+            osc_el for osc_el in grp.findall("messages/osc")
+            if osc_el.get("receive") == "1"
+            and osc_el.find("path/partial/value") is not None
+            and (osc_el.find("path/partial/value").text or "").startswith("/armed/")
+        ]
+        assert len(armed_msgs) == 1, (
+            f"pad GROUP '{grp_name}' must have exactly 1 /armed/* receive msg "
+            f"on the GROUP itself, got {len(armed_msgs)}"
+        )