fix: stale responses, double submits and leaked listeners

web/js/api-client.js wraps fetch with one failure path (ApiError for non-2xx,
success:false and non-JSON bodies) and latestOnly(), which aborts the previous
in-flight request and resolves superseded calls to STALE. The admin search and
recent-page loads share one guard, the gallery page load has its own, so fast
typing or clicking can no longer paint an older result over a newer one.

In-place prompt editing used a blur listener with {once:true} plus a keydown
listener added on every edit, which sent the PUT twice and stacked handlers.
The list now has one keydown/focusout pair bound at construction and
finishEdit() clears the edit state before touching the element, so a save is
sent exactly once. Mutations re-fetch the page currently shown (refreshList)
instead of calling search(), and delete, bulk delete, edit, restore and scan no
longer reload the whole page.

Pagination state is committed only after a successful fetch via the pure
ListState.nextPageState(current, response) in both admin and gallery, so a
failed or aborted page request leaves the current page intact. The gallery
lightbox removed its keydown handlers on a non-existent 'remove' event; a
MutationObserver now drops them when the modal leaves the document.

web/js/sse-stream.js reads server-sent events over fetch so POST-only progress
endpoints can stream.

web/admin.html

@@ -6,6 +6,9 @@
     <title>PromptManager - Admin Dashboard</title>
     <script src="/prompt_manager/js/theme-bridge.js"></script>
     <script src="/prompt_manager/js/html-escape.js"></script>
+    <script src="/prompt_manager/js/api-client.js"></script>
+    <script src="/prompt_manager/js/list-state.js"></script>
+    <script src="/prompt_manager/js/sse-stream.js"></script>
     <script src="/prompt_manager/js/data-actions.js"></script>
     <link rel="stylesheet" href="lib/tailwind/comfyui-theme.css">
     <link rel="stylesheet" href="lib/tailwind/styles.css">
@@ -444,6 +447,11 @@
                                 <p class="text-xs text-pm-muted mt-1">Get your key from <a href="https://civitai.com/user/account" target="_blank" class="text-pm-accent hover:underline">civitai.com/user/account</a></p>
                             </div>
 
+                            <label class="mt-1 flex items-center gap-1.5 text-xs text-pm-secondary cursor-pointer">
+                                <input type="checkbox" id="clearCivitaiKey" class="w-3.5 h-3.5 text-pm-accent bg-pm-input border-pm rounded focus:ring-pm-accent">
+                                <span>Clear the stored key on save</span>
+                            </label>
+
                             <button id="loraImportBtn" type="button"
                                     class="mt-1 flex items-center gap-1 text-xs text-pm-accent hover:text-pm-accent-hover">
                                 <svg class="w-3.5 h-3.5" fill="none" stroke="currentColor" viewBox="0 0 24 24">