B1-5..B1-20: distill remaining code behaviors into specs (rendering.allium, post/media/task/generation/editor specs)

specs/editor_media.allium

@@ -130,9 +130,15 @@ surface MediaEditorSurface {
     @guarantee TranslationsSection
         -- Shown only when language is set.
         -- List of existing translations: flag emoji + language name + title.
-        -- Per-translation actions: click to edit inline, refresh button, delete button.
+        -- Per-translation actions: click to edit (opens modal), refresh button, delete button.
         -- "No translations" message when list is empty.
 
+    @guarantee TranslationEditModal
+        -- Editing a translation opens a modal dialog ("Edit Translation"), not
+        --   an inline form. Hidden language field plus Title, Alt Text, and
+        --   Caption (textarea) inputs. Footer: Cancel and Save buttons.
+        -- Save persists the translation; Cancel/close discards.
+
     @guarantee LinkedPostsSection
         -- "Link to Post" button opens inline post picker overlay.
         -- List of currently linked posts with document icon. Click navigates to post tab.
@@ -214,8 +220,9 @@ rule MediaLinkToPost {
 
 rule MediaTranslationEdit {
     when: MediaTranslationEditClicked(media_id, language)
-    -- Loads translation fields inline (title, alt, caption) for that language
-    -- Edit in place, save persists to translated sidecar {path}.{lang}.meta
+    -- Opens the "Edit Translation" modal pre-filled with the translation's
+    --   title, alt, and caption for that language
+    -- Save persists to DB + translated sidecar {path}.{lang}.meta; Cancel discards
 }
 
 rule MediaTranslationRefresh {