feat(files): file-row click opens editor via URL-addressable modal

files-overlay.js no longer fetches /files/content JSON and populates
the inline <dialog>; it calls window.openModal(<edit-url>) which the
modal-router handles end-to-end. Binary files retain the old inline
dialog path (binary replace deferred from pilot scope).

Added document-level event delegation for .files-editor-save and
.files-editor-delete inside #modal-content so save/delete work on the
server-rendered editor DOM (reads data-rel-path from the textarea;
calls window.__filesEditor.getValue() for content; calls closeModal()
on success). The inline dialog's own save/delete handlers are untouched
and continue to serve the create-new-file and binary-replace flows.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

l4d2web/l4d2web/static/js/files-overlay.js

@@ -589,6 +589,57 @@
     }
   });
 
+  // ---------- modal-content save / delete (URL-addressable modal) ----------
+  // The new server-rendered editor (loaded into #modal-content) has its own
+  // .files-editor-save and .files-editor-delete buttons. Those are not the
+  // same elements as editorEls.saveBtn / editorEls.deleteBtn (which live in
+  // the old inline dialog still present for create-new-file / binary flows).
+  // Use event delegation so the handlers fire on dynamically swapped content.
+
+  document.addEventListener("click", async (event) => {
+    const modalContent = document.getElementById("modal-content");
+    if (!modalContent) return;
+
+    const saveBtn = event.target.closest(".files-editor-save");
+    if (saveBtn && modalContent.contains(saveBtn)) {
+      const ta = modalContent.querySelector("textarea[data-rel-path]");
+      if (!ta) return;
+      const relPath = ta.dataset.relPath;
+      if (!relPath) return;
+      const content = (window.__filesEditor && window.__filesEditor.getValue)
+        ? window.__filesEditor.getValue()
+        : ta.value;
+      const r = await postJson(`${baseUrl}/files/save`, { path: relPath, content });
+      if (r.ok) {
+        if (typeof window.closeModal === "function") window.closeModal();
+        scheduleRefresh(parentOf(relPath));
+      } else {
+        alert((r.body && r.body.error) || `Save failed (HTTP ${r.status}).`);
+      }
+      return;
+    }
+
+    const deleteBtn = event.target.closest(".files-editor-delete");
+    if (deleteBtn && modalContent.contains(deleteBtn)) {
+      const ta = modalContent.querySelector("textarea[data-rel-path]");
+      if (!ta) return;
+      const relPath = ta.dataset.relPath;
+      if (!relPath) return;
+      if (!confirm(`Delete ${relPath}?`)) return;
+      const fd = new FormData();
+      fd.append("path", relPath);
+      fd.append("csrf_token", csrfToken);
+      const r = await postForm(`${baseUrl}/files/delete`, fd);
+      if (r.ok) {
+        if (typeof window.closeModal === "function") window.closeModal();
+        scheduleRefresh(parentOf(relPath));
+      } else {
+        alert((r.body && r.body.error) || `Delete failed (HTTP ${r.status}).`);
+      }
+      return;
+    }
+  });
+
   // ---------- new-folder modal --------------------------------------------
 
   function openNewFolder(targetFolder) {
@@ -994,7 +1045,20 @@
       window.location.href = url;
     } else if (op === "edit") {
       const editable = action.dataset.editable === "1";
-      openEditorForFile(path, editable);
+      if (editable) {
+        // Editable text files: open via URL-addressable modal.
+        const editUrl = `/overlays/${overlayId}/files/edit?path=${encodeURIComponent(path)}`;
+        if (typeof window.openModal === "function") {
+          window.openModal(editUrl);
+        } else {
+          // Graceful fallback if modal-router didn't load — full-page navigation
+          // still hits the same route and renders the standalone editor page.
+          window.location.href = editUrl;
+        }
+      } else {
+        // Binary files: keep old inline dialog (binary replace deferred from pilot).
+        openEditorForFile(path, false);
+      }
     } else if (op === "delete") {
       const kind = action.dataset.rowKind;
       const name = action.dataset.rowName || basename(path);