[Sync] replace the flat layout with the unified stow tree

Supersedes the old flat .config/ layout (last published 2026-06-28) with the
private repo's structure: one shared base plus per-host overlays.

- packages: common/ gui/ lw/ fl/ wm/ plus install.sh and bin/ tooling
  (dotsync, reconcile-hyde.sh)
- new README covering the layout, deploy order and the HyDE dependency
- current HyDE waybar rig (layouts/, cava), pi agent extensions, claude/
  config, tmux, presenterm, aichat roles
- fish: kp (keepassxc-cli + fzf picker, db path from $KP_DB) and
  bind_M_n_history (alt+1..9 recalls the nth history entry)
- drops cruft that should never have been tracked: the duplicate top-level
  .pi/ copy, btop.log, zellij config.kdl.bak, fish_variables
- .pi/agent/auth.json is gitignored; auth.json.example ships instead

Host-specific work sessions and the personal backlog stay in the private
tree. Endpoint locators in the llamacpp/whisper guides are placeholders
($SERVER, <own-domain>) — the guides themselves stay, since they are the
useful part.

wm/.config/hypr/host.conf

@@ -0,0 +1,15 @@
+# wm host extras (sourced last by ~/.config/hypr/hyprland.conf)
+source = ~/.config/hypr/nvidia.conf
+
+# THEME OVERRIDES — personal deltas on top of wm's themes/theme.conf (tracked in this
+# overlay while wm's HyDE is old enough to hard-source it; that file is generated, so
+# anything edited in there is lost on the next theme switch — keep the deltas here,
+# where they are sourced after every theme file and therefore win).
+general {
+    gaps_in = 2
+    gaps_out = 4
+}
+
+decoration {
+    rounding = 8
+}