Fix UI visibility, form CSS, and quick-connect modal

- Fix drawer/modal backdrop class names and is-visible transitions
- Add protocol tab, settings tab, and command palette CSS
- Add form-section-content as CSS alias for form-section-body
- Add missing form CSS: form-hint, form-toggle, jump-host-row, preset-row
- Add btn-outline, form-input-sm, form-select-sm styles
- Replace window.prompt() with custom modal for WKWebView compatibility
- Remove diagnostic banner and instrumentation

frontend/src/js/secrets.js

@@ -29,7 +29,7 @@ class SecretPrompt {
         return new Promise((resolve, reject) => {
             this._close(); // dismiss any existing prompt
 
-            const overlay = createElement('div', 'modal-overlay');
+            const overlay = createElement('div', 'modal-backdrop');
             const modal = createElement('div', 'modal modal-secret');
 
             // Header
@@ -63,6 +63,11 @@ class SecretPrompt {
             document.body.appendChild(overlay);
             this._overlay = overlay;
 
+            requestAnimationFrame(() => {
+                overlay.classList.add('is-visible');
+                modal.classList.add('is-visible');
+            });
+
             const input = modal.querySelector('.secret-input');
             input.focus();
 
@@ -103,7 +108,7 @@ class SecretPrompt {
         return new Promise((resolve, reject) => {
             this._close();
 
-            const overlay = createElement('div', 'modal-overlay');
+            const overlay = createElement('div', 'modal-backdrop');
             const modal = createElement('div', 'modal modal-secret');
 
             const title = isNew ? 'Create Master Password' : 'Unlock Secret Store';
@@ -151,6 +156,11 @@ class SecretPrompt {
             document.body.appendChild(overlay);
             this._overlay = overlay;
 
+            requestAnimationFrame(() => {
+                overlay.classList.add('is-visible');
+                modal.classList.add('is-visible');
+            });
+
             const passInput = modal.querySelector('.master-password');
             const confirmInput = modal.querySelector('.master-confirm');
             const errorEl = modal.querySelector('.secret-error');
@@ -211,7 +221,7 @@ class SecretPrompt {
         return new Promise((resolve) => {
             this._close();
 
-            const overlay = createElement('div', 'modal-overlay');
+            const overlay = createElement('div', 'modal-backdrop');
             const modal = createElement('div', 'modal modal-secret modal-hostkey');
 
             const header = createElement('div', 'modal-header');