fix: bring dashboard tag cloud and sections into bDS2 parity (closes #11)

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

specs/editor_misc.allium

@@ -50,7 +50,6 @@ value DashboardTimelineMonth {
 
 value DashboardTagCloud {
     tags: List<DashboardTag>
-    overflow_count: Integer?            -- "and N more" when > config.dashboard_max_tags
 }
 
 value DashboardTag {
@@ -106,7 +105,6 @@ surface DashboardSurface {
             t.name
             t.count
             t.color
-        dash.tag_cloud.overflow_count when dash.tag_cloud.overflow_count != null
         for c in dash.category_cloud.categories:
             c.name
             c.count
@@ -131,16 +129,18 @@ surface DashboardSurface {
         -- Bar height proportional to max count.
 
     @guarantee TagCloud
-        -- Up to config.dashboard_max_tags tags, sorted alphabetically.
+        -- Tags counted from post tags (trimmed, non-empty entries).
+        -- The config.dashboard_max_tags most-used tags are shown, sorted alphabetically.
         -- Font size scaled config.dashboard_tag_min_font to config.dashboard_tag_max_font px
-        --   based on post count.
+        --   relative to the min/max post counts of the displayed tags.
         -- Tags with colours get coloured background with contrast text.
         -- Hover title shows post count.
-        -- "and N more" text when overflow_count > 0.
+        -- Section hidden when there are no tags.
 
     @guarantee CategoryCloud
-        -- All categories as badge-like tags.
-        -- Each shows category name + count.
+        -- All categories as badge-like tags, sorted by post count descending
+        --   then name ascending.
+        -- Each shows category name + count. Section hidden when empty.
 
     @guarantee RecentPosts
         -- Last config.dashboard_recent_count posts by updatedAt descending.