Status line: band shape, drop token_in/token_out segments

Band merges the segment groups into one row above the editor and paints
the labeled inline context meter (60% - 200K); the session title rides
the working row. Cumulative token totals live in /session - off the bar.
Docs and changelog updated to the band final state.

agent/config.yml

@@ -18,7 +18,7 @@ modelRoles:
   memory: llamacpp (dankclaw-3090)/frank-zealot:medium
 symbolPreset: nerd
 composer:
-  shape: claude
+  shape: band
 theme:
   dark: dark-terminal
   light: light
@@ -115,8 +115,6 @@ statusLine:
     - git
     - pr
   rightSegments:
-    - token_in
-    - token_out
     - cost
     - context_pct
     - time_spent