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/examples/cursor_theme_setup.md

@@ -0,0 +1,5 @@
+To apply cursor/theme changes without full logout:
+1. Edit `~/.config/niri/cfg/misc.kdl`
+2. Run `kill -USR1 $(pidof niri)`
+3. Verify with `niri msg cursor` or visual check.
+Avoids full session restart and preserves app state.