add image-viewer card + clide image show verb

Drives an image inline into the Claude conversation log over the same
bus-publish path as ui.toast/ui.open, keeping the dispatcher handler
Flutter-free. The card is display-only per D-78; the verb registers a
CommandSchema so it surfaces in clide capabilities for T-248 discovery.

Closes T-249.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -18,6 +18,11 @@ heading, and (b) bumping `pubspec.yaml` `version:` in the same commit.
 
 ### Added
 
+- Image cards in the Claude conversation log: `clide image show <path>
+  [--caption …]` renders an image inline (PNG/JPG/JPEG/GIF/WebP/BMP),
+  clide-owned and display-only (D-78). The path is resolved workspace-relative
+  and must exist; the verb registers in the dispatcher so it shows up in `clide
+  capabilities`. (T-249)
 - `clide capabilities` lists the live command surface as JSON (every verb with
   its subsystem + argument schema), reflected from the dispatcher so it never
   drifts. A new `/clide` skill points Claude at it for discovery. (T-248)