feat: show update available when catalog version differs from installed

Catalog partial now compares catalog version vs installed plugin.yaml version.
Gold border + "Update available — installed vX.Y.Z" badge when newer.
Update button uses btn-warn styling. Route passes installed_versions dict.

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

fabledscryer/settings/routes.py

@@ -256,11 +256,13 @@ async def plugins_catalog():
 
     discovered = _discover_plugins()
     installed_names = {p["_dir"] for p in discovered}
+    installed_versions = {p["_dir"]: p.get("version", "0.0.0") for p in discovered}
 
     return await render_template(
         "settings/_catalog_partial.html",
         catalog=catalog,
         installed_names=installed_names,
+        installed_versions=installed_versions,
         loaded_names=_LOADED_PLUGINS,
         error=error,
     )

fabledscryer/templates/settings/_catalog_partial.html

@@ -12,17 +12,27 @@
     {% for plugin in catalog %}
     {% set is_installed = plugin.name in installed_names %}
     {% set is_loaded = plugin.name in loaded_names %}
-    <div class="card" style="margin-bottom:0;padding:1rem 1.25rem;">
+    {% set installed_ver = installed_versions.get(plugin.name, "") %}
+    {# update_available: catalog version is strictly newer than what's on disk #}
+    {% set update_available = is_installed and installed_ver and installed_ver != plugin.version %}
+
+    <div class="card" style="margin-bottom:0;padding:1rem 1.25rem;{% if update_available %}border-color:var(--gold);{% endif %}">
       <div style="display:flex;align-items:flex-start;gap:1rem;">
         <div style="flex:1;min-width:0;">
           <div style="display:flex;align-items:center;gap:0.6rem;flex-wrap:wrap;">
             <span style="font-weight:600;color:var(--text);font-size:0.9rem;">{{ plugin.name }}</span>
             <span style="font-size:0.75rem;color:var(--text-muted);">v{{ plugin.version }}</span>
-            {% if is_loaded %}
+
+            {% if update_available %}
+            <span class="badge badge-gold" style="font-size:0.68rem;">
+              Update available — installed v{{ installed_ver }}
+            </span>
+            {% elif is_loaded %}
             <span class="badge badge-green" style="font-size:0.68rem;">Active</span>
             {% elif is_installed %}
             <span class="badge" style="background:var(--bg-elevated);color:var(--text-muted);font-size:0.68rem;">Installed</span>
             {% endif %}
+
             {% for tag in plugin.tags %}
             <span style="font-size:0.68rem;padding:0.1em 0.4em;background:var(--bg-elevated);color:var(--text-muted);border-radius:3px;">{{ tag }}</span>
             {% endfor %}
@@ -46,8 +56,8 @@
              class="btn btn-ghost btn-sm" style="font-size:0.78rem;">Source</a>
           {% endif %}
 
-          {% if is_loaded %}
+          {% if update_available %}
-          {# Already active — update available if versions differ #}
+          {# Installed but outdated — offer update (download + restart) #}
           <form method="post"
                 action="/settings/plugins/install/{{ plugin.name }}"
                 hx-post="/settings/plugins/install/{{ plugin.name }}"
@@ -56,9 +66,12 @@
                 style="margin:0;">
             <input type="hidden" name="download_url" value="{{ plugin.download_url }}">
             <input type="hidden" name="checksum_sha256" value="{{ plugin.checksum_sha256 }}">
-            <button type="submit" class="btn btn-ghost btn-sm" style="font-size:0.78rem;">Update</button>
+            <button type="submit" class="btn btn-warn btn-sm" style="font-size:0.78rem;">Update</button>
           </form>
 
+          {% elif is_loaded %}
+          {# Active and up to date — no action needed #}
+
           {% elif is_installed %}
           {# Installed but not active — offer hot-reload #}
           <form method="post"