Polish journal entry save buttons and header controls

- Add hover titles to all save buttons
- Match warning color scheme across floating, inline, and header save buttons
- Fix floating save button visibility (Tailwind v4 hidden/md:inline-flex conflict)
- Hide floating save when no unsaved changes using {#if}
- Hide Config button when not in admin edit mode
- Remove the mobile/backup explicit Save button from header (redundant)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/lib/ae_elements/AE_AITools.svelte

@@ -165,7 +165,7 @@ function handle_save() {
             <span class="text-sm">Processing...</span>
         {:then}
             <BotMessageSquare class="mr-1 inline-block" size="1.2em" />
-            <span class="text-sm">Summarize</span>
+            <span class="text-sm hidden">Summarize</span>
         {:catch}
             <span class="text-sm text-red-500">Error</span>
         {/await}
@@ -181,6 +181,7 @@ function handle_save() {
         class="btn btn-sm preset-tonal-surface shadow-md"
         title="AI Settings">
         <Settings size="1.2em" />
+        <span class="text-sm hidden">Settings</span>
     </button>
 
     <!-- Unified AI Modal -->