Switch the theme live

Widgets copy their colors when they are created, so they now get role
tokens (one unique RGB value per role) instead of colors, and a wrapper
around the tcell screen replaces the tokens with the current theme's
colors in SetContent. Changing the theme in the Config view swaps that
table; the next draw recolors everything. Poster colors that equal a
token are nudged off it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019reK4DUGYqDUjniWYJvwUW

README.md

@@ -30,7 +30,7 @@ A terminal UI to search for movies and series with [Radarr](https://radarr.video
 - **Config (F6)**: edit everything in the config file from inside the program, in one list you move
   through with the arrow keys: service addresses and API keys, the add-form defaults, refresh interval, posters, theme, notifications. *Test*
   checks the values you typed before saving; *Save* writes the file (permissions kept, `0600` for a
-  new file) and applies the changes at once (the theme at the next start). Values that come from `ARR_TUI_*`
+  new file) and applies the changes at once, no restart. Values that come from `ARR_TUI_*`
   environment variables are greyed out and are never written to the file.
 - **Log (F7)**: actions report through popups that fade away; the log keeps the history.
 - **Download notifications**: a popup (and a log entry) when a SABnzbd download finishes or fails,
@@ -39,8 +39,8 @@ A terminal UI to search for movies and series with [Radarr](https://radarr.video
   `"bell": true` also rings the terminal bell.
 - **Themes**: fixed dark and light color sets that look the same in every terminal, whatever its
   color theme. `"ui": {"theme": ...}` is `auto` (default: light when the terminal reports a light
-  background, else dark), `dark` or `light`; it can also be set in the Config view and applies at the
-  next start.
+  background, else dark), `dark` or `light`; it can also be switched in the Config view, which
+  recolors everything at once.
 - Connection indicators for all three services in the top right; `F9` shows every key.
 
 Requires Radarr/Sonarr v3+ API (Radarr 5/6, Sonarr 4) and SABnzbd 4+. Only Usenet releases are