[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.

common/.config/fish/functions/lk.fish

@@ -0,0 +1,18 @@
+function lk --description 'linux knowledge' 
+	set -l DB "$HOME/projects/dmz/soft/lk/db.rec"
+	set -l passes 0
+	set -l count 0
+	set -l query ""
+
+	while test $passes -lt 2; and test $count -eq 0
+		set query (recsel "$DB" -p aim,tag | recsel -iq "$query" -CP aim,tag | sort -u | fzf --preview="recsel \"$DB\" -e \"aim~{}\" | bat")
+		if test -n "$query"
+			set count (recsel "$DB" -q "$query" -c)
+		end
+		set passes (math $passes + 1)
+	end
+
+	if test $count -eq 1
+		recsel "$DB" -q "$query" | recfmt -f "$HOME/projects/dmz/soft/lk/lists.fmt" | less
+	end
+end