post.html header prose branches on viewer-vs-owner: invitees see "shared with me, @viewer the {title}" + "created by @owner the {title}" instead of the owner-centric "just me / shared between" lines; owner view unchanged — TDD

- billboard.views.view_post adds viewer_is_owner + other_recipients context vars. is_real_invitee = (auth AND post has owner AND viewer != owner). Anon viewers + ownerless-post legacy path fall through to owner-style rendering (which renders empty gracefully via the at_handle / display_name AnonymousUser guards).
  - other_recipients = post.shared_with.exclude(viewer) when invitee; .all() otherwise.
  - post.html .post-header branches:
    • viewer_is_owner: existing prose ("just me, @owner …" / "shared between {recipients} & me, @owner …").
    • sole invitee: "shared with me, @viewer the {viewer.title}" + "created by @owner the {owner.title}".
    • multi invitee: "shared with {other_recipients}" + "& me, @viewer the {viewer.title}" + "created by @owner the {owner.title}".
  - lyric_extras at_handle + display_name: guard against AnonymousUser (no .email attribute) — return "" rather than crash. Preserves the Percival ch. 18 anon-views-ownerless-post path.
  - 12 new ITs in test_post_invitee_view (context vars: viewer_is_owner, other_recipients exclude/include; template prose: sole + multi invitee phrasing, owner unchanged).
  - 878 IT regression + 8 post-html FT regression green (1 Marionette flake on multi-run that passes in isolation).

Code architected by Disco DeDisco <discodedisco@outlook.com>
Git commit message Co-Authored-By:
Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/templates/apps/billboard/post.html

@@ -14,14 +14,27 @@
 <div class="post-page">
     <header class="post-header">
         <h3 class="post-title">{{ post.title }}</h3>
-        {% with recipients=post.shared_with.all %}
-            {% if recipients %}
-                <p class="post-shared-recipients">shared between {% for r in recipients %}<span class="post-recipient post-attribution">{{ r|at_handle }}</span>{% if not forloop.last %}, {% endif %}{% endfor %}</p>
+        {% if viewer_is_owner %}
+            {# Owner viewing — owner-centric prose. "shared between" lists  #}
+            {# every recipient; the self line is the owner's own handle.    #}
+            {% if other_recipients %}
+                <p class="post-shared-recipients">shared between {% for r in other_recipients %}<span class="post-recipient post-attribution">{{ r|at_handle }}</span>{% if not forloop.last %}, {% endif %}{% endfor %}</p>
                 <p class="post-shared-self">&amp; me, <span class="post-attribution">{{ post.owner|at_handle }} the {{ post.owner.active_title_display }}</span></p>
             {% else %}
                 <p class="post-shared-self">just me, <span class="post-attribution">{{ post.owner|at_handle }} the {{ post.owner.active_title_display }}</span></p>
             {% endif %}
-        {% endwith %}
+        {% else %}
+            {# Invitee viewing — "shared with" prose centred on the viewer   #}
+            {# (request.user). Sole invitee collapses to a single line; the  #}
+            {# "created by …" line attributes the post to its founder.      #}
+            {% if other_recipients %}
+                <p class="post-shared-recipients">shared with {% for r in other_recipients %}<span class="post-recipient post-attribution">{{ r|at_handle }}</span>{% if not forloop.last %}, {% endif %}{% endfor %}</p>
+                <p class="post-shared-self">&amp; me, <span class="post-attribution">{{ request.user|at_handle }} the {{ request.user.active_title_display }}</span></p>
+            {% else %}
+                <p class="post-shared-self">shared with me, <span class="post-attribution">{{ request.user|at_handle }} the {{ request.user.active_title_display }}</span></p>
+            {% endif %}
+            <p class="post-created-by">created by <span class="post-attribution">{{ post.owner|at_handle }} the {{ post.owner.active_title_display }}</span></p>
+        {% endif %}
     </header>
 
     <ul id="id_post_table" class="post-lines">