feat: plugins config APIs

resources/web/dialog/PluginsDialog/index.html

@@ -151,16 +151,27 @@
                 <div id="configEditor" class="config-editor" hidden>
                   <textarea id="configText" class="config-textarea thin-scroll" spellcheck="false"
                     autocomplete="off" autocapitalize="off" aria-label="Capability configuration (JSON)"></textarea>
-                  <div class="config-editor-footer">
-                    <span id="configValidation" class="config-validation" role="status" aria-live="polite"></span>
-                    <button id="configSaveBtn" class="ButtonStyleConfirm ButtonTypeChoice" type="button">Save</button>
-                  </div>
                 </div>
                 <!-- Custom capability UI. Sandboxed without allow-same-origin, so the plugin's HTML
                      runs in an opaque origin: it cannot touch this page, and the only host surface
                      it gets is the window.orca getConfig/saveConfig bridge injected into srcdoc. -->
                 <iframe id="configCustom" class="config-custom" title="Plugin configuration"
                   sandbox="allow-scripts" referrerpolicy="no-referrer" hidden></iframe>
+                <!-- Host chrome for both editors, not just the JSON one: a capability with a custom
+                     UI needs Restore just as much, and keeping it here leaves it out of the plugin's
+                     HTML and off the JS bridge. Save and the validation message belong to the JSON
+                     editor alone (a custom UI saves through its own controls), so they are hidden
+                     when a custom UI is showing. -->
+                <div id="configFooter" class="config-view-footer" hidden>
+                  <span id="configValidation" class="config-validation" role="status" aria-live="polite"></span>
+                  <div class="config-actions">
+                    <button id="configRestoreBtn" class="ButtonStyleRegular ButtonTypeChoice" type="button"
+                      title="Discard the settings saved for this capability and restore the plugin's defaults">
+                      Restore defaults
+                    </button>
+                    <button id="configSaveBtn" class="ButtonStyleConfirm ButtonTypeChoice" type="button">Save</button>
+                  </div>
+                </div>
               </div>
             </div>
           </section>

resources/web/dialog/PluginsDialog/index.js

@@ -70,7 +70,15 @@ function OnInit() {
 
   document.getElementById("configSidebar")?.addEventListener("click", OnConfigSidebarClick);
   document.getElementById("configSaveBtn")?.addEventListener("click", SaveCapabilityConfig);
-  document.getElementById("configText")?.addEventListener("input", ValidateConfigText);
+  document.getElementById("configRestoreBtn")?.addEventListener("click", RestoreCapabilityConfig);
+
+  const configText = document.getElementById("configText");
+  // why: common.js installs a document-level onkeydown that cancels the default action of every key
+  //      (returnValue=false) to block webview shortcuts; on the way up it also swallows typing. Stop
+  //      the editor's keydowns from bubbling to it so the textarea stays editable, leaving the global
+  //      guard intact. Same treatment as the search field (see plugin-search.js).
+  configText?.addEventListener("keydown", (event) => event.stopPropagation());
+  configText?.addEventListener("input", ValidateConfigText);
   // The custom capability UI is sandboxed into an opaque origin, so it reaches us only through
   // postMessage. Match on the frame's own contentWindow rather than the origin (which is "null"
   // for a sandboxed frame) and ignore anything else on the channel.
@@ -939,12 +947,14 @@ function RequestCapabilityConfig() {
 }
 
 // Empties both editors, so nothing from the previously selected capability can linger while the
-// next one is still in flight.
+// next one is still in flight. The footer goes with them: until a config has actually loaded there
+// is nothing to save or restore.
 function ClearCapabilityConfigView() {
   const editor = document.getElementById("configEditor");
   const custom = document.getElementById("configCustom");
   const text = document.getElementById("configText");
   const error = document.getElementById("configError");
+  const footer = document.getElementById("configFooter");
 
   if (editor)
     editor.hidden = true;
@@ -958,6 +968,8 @@ function ClearCapabilityConfigView() {
     error.hidden = true;
     error.textContent = "";
   }
+  if (footer)
+    footer.hidden = true;
   SetConfigValidation("");
 }
 
@@ -986,6 +998,10 @@ function ApplyCapabilityConfig(payload) {
   const config = (payload && typeof payload.config === "object" && payload.config !== null) ? payload.config : {};
   const html = String(payload?.custom_html || "");
 
+  // Restore is host chrome and applies to either editor; Save and the validation message belong to
+  // the JSON editor, since a custom UI saves through its own controls via the bridge.
+  ShowConfigFooter(!html);
+
   if (html) {
     // A capability with its own UI: hand it the config through the bridge, never the raw file.
     if (custom) {
@@ -1010,6 +1026,21 @@ function ApplyCapabilityConfig(payload) {
   SetConfigValidation("");
 }
 
+// Reveals the footer for the loaded capability. `withEditorControls` is false for a custom UI,
+// leaving Restore on its own.
+function ShowConfigFooter(withEditorControls) {
+  const footer = document.getElementById("configFooter");
+  const save = document.getElementById("configSaveBtn");
+  const validation = document.getElementById("configValidation");
+
+  if (footer)
+    footer.hidden = false;
+  if (save)
+    save.hidden = !withEditorControls;
+  if (validation)
+    validation.hidden = !withEditorControls;
+}
+
 function SetConfigValidation(message) {
   const node = document.getElementById("configValidation");
   const save = document.getElementById("configSaveBtn");
@@ -1054,6 +1085,21 @@ function SaveCapabilityConfig() {
   });
 }
 
+// Asks the native side to write the capability's default config over whatever is stored. The
+// defaults come from the capability's get_default_config(), never from this page — the host does not
+// know what a given plugin considers default. The native side confirms before discarding anything,
+// and replies with the same "saved" payload, so both editors reload from what was persisted.
+function RestoreCapabilityConfig() {
+  if (!selectedPluginId || !selectedCapabilityName)
+    return;
+
+  SendMessage("restore_capability_config", {
+    plugin_key: selectedPluginId,
+    capability_name: selectedCapabilityName,
+    capability_type: selectedCapabilityType
+  });
+}
+
 function ApplyCapabilityConfigSaved(payload) {
   if (!IsCurrentCapability(payload))
     return;

resources/web/dialog/PluginsDialog/styles.css

@@ -1182,9 +1182,9 @@ body {
   min-height: 0;
   padding: 8px;
   box-sizing: border-box;
-  /* common.css applies `user-select: none` to *, which in WebKit also stops a textarea taking a
-     caret — the editor would be focusable but impossible to type into. Editable surfaces have to
-     opt back in (same as include/xterm/xterm.css does for the terminal). */
+  /* common.css applies `user-select: none` to *, so without this the user could type into the
+     editor but not select, drag or copy what they had typed. (What blocks typing is the global
+     onkeydown guard in common.js — see the keydown handler in index.js.) */
   -webkit-user-select: text;
   user-select: text;
   border: 1px solid var(--border);
@@ -1204,13 +1204,29 @@ body {
   border-color: var(--main-color);
 }
 
-.config-editor-footer {
+.config-view-footer {
   display: flex;
   align-items: center;
   justify-content: space-between;
   gap: 8px;
 }
 
+.config-view-footer[hidden] {
+  display: none;
+}
+
+/* Restore sits immediately left of Save, both pinned right; the validation message takes the
+   remaining space on the left. */
+.config-actions {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+}
+
+.config-actions > button[hidden] {
+  display: none;
+}
+
 .config-validation {
   color: var(--muted);
   font-size: 11px;