Update changelog and roadmap for v0.5.2 polish fixes

Add dark mode theming, dialog dropdown clipping, and user menu scale
fix entries to changelog. Add extreme UI scale polish to backlog.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -47,6 +47,15 @@ All notable changes to Switchboard Core are documented here.
 - **Creator display name**: `chat-core.create()` now accepts
   `creator_display_name` so the conversation creator shows a readable name
   in the participant sidebar instead of a raw UUID.
+- **Chat dark mode theming**: Replaced non-existent CSS variable names with
+  actual theme tokens from `variables.css`. Fixes invisible text and wrong
+  backgrounds in dark mode.
+- **Dialog dropdown clipping**: UserPicker autocomplete dropdown in dialogs
+  (New Conversation, Add Participant) no longer clipped by `overflow: auto`
+  on `.sw-dialog__body`.
+- **User menu at scaled UI**: Menu primitive now divides anchor coordinates
+  and viewport dimensions by `sw.shell.getScale()` to compensate for CSS
+  `transform: scale()` on `#surfaceInner`. Fixes menu clipping at 110%+.
 
 ### Changed
 

ROADMAP.md

@@ -386,6 +386,7 @@ participation is post-MVP.
 | Item | Description |
 |------|-------------|
 | "Requires Review" filter | Dropdown filter option or dedicated button for `pending_review` packages. Useful when the package list grows long. |
+| Extreme UI scale polish | At 150%+ scale: user menu items overflow viewport (need scroll), topbar elements clipped. Ensure all surfaces and menus are usable at scale extremes (80%–200%). |
 
 ### v0.5.4 — Package Updates (planned)