feat(matrix): autofill name on load

Emit /matrix/loaded <name> at each user-facing load point (the /matrix/load
OSCdef, the queued branch of ~matWrapStep firing at the wrap, and the
not-playing fallback in /matrix/loadnext) - not from the shared ~matLoad,
to avoid spamming during the boot autoload. The web fills #matrix-name from
it, so SAUVER updates the loaded matrix in place. For CHARGER SUIVANT the
name tracks the actual swap (at the wrap), never the merely-armed preset.

VALIDATE 84/84, test_matnames PASS, node --check + 29 web tests pass.

sound_algo/data_only/matrix.scd

@@ -410,8 +410,10 @@ File.exists(~matDir).not.if({ ("mkdir -p " ++ ~matDir.quote).systemCmd });
 //    ÉVOLUE mutates it; otherwise evolve mutates as before. --
 ~matWrapStep = {
     ~matQueuedLoad.notNil.if({
-        ~matLoad.(~matQueuedLoad);
+        var name = ~matQueuedLoad;
+        ~matLoad.(name);
         ~matQueuedLoad = nil;
+        ~toscSend !? { ~toscSend.("/matrix/loaded", name) };   // name tracks the actual swap
         ~toscSend !? { ~toscSend.("/matrix/queued", "") };
     }, {
         ~matEvolve.if({ ~matEvolveStep.() });
@@ -961,8 +963,10 @@ OSCdef(\mat_save, { |msg, time, addr|
 }, '/matrix/save');
 
 OSCdef(\mat_load, { |msg, time, addr|
+    var name = msg[1].asString;
     ~toscTouch !? { ~toscTouch.(addr) };
-    ~matLoad.(msg[1].asString)
+    ~matLoad.(name);
+    ~toscSend !? { ~toscSend.("/matrix/loaded", name) };       // web: track loaded name
 }, '/matrix/load');
 
 OSCdef(\mat_loadnext, { |msg, time, addr|
@@ -973,6 +977,7 @@ OSCdef(\mat_loadnext, { |msg, time, addr|
         ~toscSend !? { ~toscSend.("/matrix/queued", name) };
     }, {
         ~matLoad.(name);                                        // not playing -> load now
+        ~toscSend !? { ~toscSend.("/matrix/loaded", name) };
         ~toscSend !? { ~toscSend.("/matrix/queued", "") };
     });
 }, '/matrix/loadnext');

web_realart/public/control/js/main.js

@@ -129,6 +129,12 @@ document.addEventListener("DOMContentLoaded", () => {
       matLoadNext.textContent = name.length > 0 ? "SUIVANT → " + name : "SUIVANT";
     }
   });
+  // A loaded matrix fills the name field, so SAUVER updates it in place.
+  on("/matrix/loaded", (args) => {
+    const name = (args && args[0] != null) ? String(args[0]) : "";
+    const nameInput = document.getElementById("matrix-name");
+    if (nameInput && name.length > 0) nameInput.value = name;
+  });
   const matRefresh = document.getElementById("matrix-refresh");
   if (matRefresh) matRefresh.addEventListener("click", () => send("/matrix/list"));
 });