niri(blankpad): desk-profile system, keybind rework, lid handler, noctalia config tracked

- config.kdl: display include optional=true (desk profiles link it per-desk),
  new optional switch-events.kdl include (per-host, blankpad-only)
- keybinds: swap-window-left/right on Mod+CTRL+H/L+arrows (join/exit columns
  on pass), move-column demoted to Mod+CTRL+Alt+chords; Print trio -> flameshot
  full/gui/screen (CTRL+Shift trio kept); launcher Mod+CTRL+Return -> Mod+D;
  Alt+Tab noctalia window-switcher; Mod+V clipboard panel; Mod+Shift+Space
  handy post-process; Mod+Shift+D desk cycle
- layout: preset column widths 12.5/25/33/50/67/75/87.5%
- desk-1-home.kdl: EDID-identity-keyed positions (M34 + eDP long names; PM1601
  connector placeholder pending EDID capture), focus-at-startup M34-first
- desk-2-portable.kdl: skeleton, EDID capture TODO
- switch-events: lid-close -> noctalia session lock-and-suspend
- autostart: handy --start-hidden (replaces Handy self-autostart)
- noctalia config.toml + settings.toml now tracked
- zz-blankpad display.kdl retired to .AGENTTRASH (superseded by desk-1-home)
niri validate: pass (assembled blankpad layout)

dotfiles/noctalia/.config/noctalia/config.toml

@@ -0,0 +1,5 @@
+[shell]
+polkit_agent = true
+
+[wallpaper]
+directory = "/home/blank/.local/share/noctalia/wallpapers"