Refine journal entry config

Polish the Journal Entry Config modal to match the desired section outline, hide alert messaging unless enabled, update the shared draft typing for entry flows, and replace deprecated privacy icons.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/lib/elements/element_editor_codemirror.svelte

@@ -13,7 +13,7 @@ import { ensure_CodeMirror_modules } from './codemirror_modules';
 // Icons (Standardized to Lucide where possible, or FontAwesome placeholders)
 import { Bold, Code, Italic, List } from '@lucide/svelte';
 interface Props {
-    content?: string;
+    content?: string | null;
     new_content?: string;
     placeholder?: string;
     theme_mode?: 'light' | 'dark';