feat: v0.6.0 light mode, command palette, dialogs, toasts

- Light mode with the house ☀/◐ toggle and lt_theme preference; light
  terminal palette; Claude runs with dark-ansi so its colours follow the
  palette; tmux and the statusLine use ANSI colours.
- Command palette (⌕, Ctrl+Shift+P) with session, terminal, view, link and
  help commands.
- .lt-modal dialogs for new/rename/end and a keyboard shortcuts sheet.
- .lt-toast results for actions, uploads, copy and CI.
- ttyd dropped the reply of fast one-shot commands; replies now wait for the
  browser to hang up, and the client hangs up as soon as it has one.
- Sessions panel re-fetches after an action instead of reusing a stale poll.

Closes #31
Closes #32
Closes #33
Closes #34
Closes #35

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

libexec/devdesk-statusline

@@ -38,12 +38,13 @@ if [[ $session =~ ^[A-Za-z0-9][A-Za-z0-9_-]{0,63}$ ]]; then
     fi
 fi
 
-# Footer line, in TDS colours: session · model · context % · cost
+# Footer line: session · model · context % · cost. ANSI colour numbers, not RGB,
+# so the browser's dark or light palette applies (devdesk#31).
 jq -rM --arg s "$session" '
-    def c($rgb; $t): "\u001b[38;2;\($rgb)m\($t)\u001b[0m";
+    def c($sgr; $t): "\u001b[\($sgr)m\($t)\u001b[0m";
     def pct: if . == null then "—" else "\(. | floor)%" end;
-    [ (if $s != "" then c("255;107;0"; "◈ \($s)") else empty end),
-      c("0;212;255"; .model.display_name // "Claude"),
-      c("127;163;191"; "ctx \(.context_window.used_percentage | pct)"),
-      c("62;96;122"; "$\((.cost.total_cost_usd // 0) * 100 | round / 100)")
-    ] | join(c("62;96;122"; " · "))' <<<"$input" 2>/dev/null || true
+    [ (if $s != "" then c("33"; "◈ \($s)") else empty end),
+      c("36"; .model.display_name // "Claude"),
+      c("37"; "ctx \(.context_window.used_percentage | pct)"),
+      c("37"; "$\((.cost.total_cost_usd // 0) * 100 | round / 100)")
+    ] | join(c("90"; " · "))' <<<"$input" 2>/dev/null || true