niri: drop untracked noctalia.kdl include; sync memory skills

- remove 'include noctalia.kdl' from shared config.kdl: the file is a
  per-host noctalia template render (colors from local palette), was
  never committed, and made every config load fail hard on hosts where
  it was absent — niri 26.04 falls back to DEFAULT config on parse
  error, silently killing keybinds/rules/layout/autostart
- theme integration now only via keybinds (noctalia msg verbs) + the
  host-local rendered files (see managed skill noctalia-template-offline-render)
- sync agent memories: delete retired memory-store skills, add new ones

agent/memories/--home-dank-.omp--/skills/niri_desktop_tweaks/SKILL.md

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+Manages niri Wayland compositor settings and noctalia v5 desktop integration. Config stored in `~/.config/niri/cfg/misc.kdl`. Reload via `niri msg reload` or `kill -USR1 $(pidof niri)`. Default browser: Firefox. Cursor: `capitaine-cursors`, size 48px. Wallpaper rotates from repo-tracked dir. Live runtime flip handled by single-instance guard.