fix: suppression boutons doublons Forge + delegation parent modal

- Retrait des 3 boutons (delete/cancel/save) de la barre Forge (doublons)
- Retrait des handlers JS associés dans editor-poc.html
- Le header parent ObsiGate reste visible quand Forge est ouvert
- Les boutons save/delete du parent délèguent à Forge via postMessage
- Forge écoute 'parent-save' et 'parent-delete' du parent
- state.editorVault/editorPath settés dans viewer.js pour le parent

frontend/js/viewer.js

@@ -525,14 +525,10 @@ export function renderFile(data) {
   forgeBtn.addEventListener("click", () => {
     var modal = document.getElementById("editor-modal");
     var container = modal.querySelector(".editor-container");
-    var headerEl = modal.querySelector(".editor-header");
-    var footerEl = modal.querySelector(".editor-footer");
     var bodyEl = document.getElementById("editor-body");
-    // Hide header/footer since Forge has its own
-    if (headerEl) headerEl.style.display = "none";
-    if (footerEl) footerEl.style.display = "none";
-    // Make container fill the modal
-    if (container) container.style.maxHeight = "100vh";
+    // Set editor state so parent buttons work
+    state.editorVault = data.vault;
+    state.editorPath = data.path;
     bodyEl.innerHTML = "";
     bodyEl.style.overflow = "hidden";
     var iframe = document.createElement("iframe");