Move frame name/mode into the page header; Calendar gets its own tab

Frame name (pencil-icon inline edit) and the Photos/Calendar mode
selector now live in the page header, shared across all four per-frame
pages instead of being buried in the Configuration form -- so renaming
a frame or flipping its mode no longer requires navigating to a
specific tab first.

Calendar settings move out of a conditionally-hidden card on the
Configuration tab into their own dedicated tab (new /frames/{id}/
calendar route), visually greyed out when the frame is in Photos mode
but still fully usable so calendar settings can be configured ahead of
switching modes. Also wires the week-start setting into the UI for the
first time (the column/backend support landed earlier but had no
control anywhere).

server/app/templates/frame_photos.html

@@ -1,7 +1,8 @@
 {% extends "app_base.html" %}
 
 {% block title %}{{ frame.name or "Frame" }} · Photos{% endblock %}
-{% block page_title %}{{ frame.name or "Frame " ~ frame.id }}{% endblock %}
+{% block page_title %}{% include "_frame_name_edit.html" %}{% endblock %}
+{% block head_actions %}{% include "_frame_mode_select.html" %}{% endblock %}
 
 {% block device_status %}{% include "_device_status_bar.html" %}{% endblock %}
 {% block tabs %}{% include "_frame_tabs.html" %}{% endblock %}
@@ -57,6 +58,7 @@
 {% block scripts %}
   <script>window.FRAME_API = {{ ("/api/frames/" ~ frame.id) | tojson }};</script>
   <script src="/static/device_status_bar.js"></script>
+  <script src="/static/frame_header.js"></script>
   <script src="/static/queue.js"></script>
   <script src="/static/frame_photos.js"></script>
 {% endblock %}