v0.8.0: TUI stabilization, command palette reverse-video highlight, hint bar redesign

- ROADMAP: consolidate all TUI work under v0.8.0 (removed premature
  v0.9.0/v0.10.x labels), restored original v0.9.0 eval harness plan
- channel-tui-view.org: Emacs-style reverse-video cursor (swap fg/bg
  instead of drawing █), hint bar now shows F:focus/MCP:count on left
  and token gauge + keybindings on right, sidebar reorganized to show
  GATE TRACE, RULES + BLOCK COUNT, COST, FILES panels
- channel-tui-main.org: command palette selection now uses reverse-video
  highlight (bg-input fg on input-fg bg, matching cursor style), fixed
  cond order so sel-p is checked before cat (all items had :category
  making sel-p unreachable), added session-cost extraction from daemon
- passepartout: export COLORTERM=truecolor for modern backend detection

passepartout

@@ -424,6 +424,8 @@ LISPEOF
         # Set character-at-a-time mode BEFORE SBCL starts
         # (uiop:run-program inside SBCL can't access the terminal)
         stty -icanon -echo -ixon 2>/dev/null
+        # Ensure COLORTERM is set for modern backend detection
+        export COLORTERM="${COLORTERM:-truecolor}"
         # Clear stale cl-tty cache to ensure latest backend-size fixes
         find ~/.cache/common-lisp -name "*.fasl" -path "*cl-tty*" -delete 2>/dev/null
         sbcl --noinform --load /tmp/tui-load.lisp