[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.

gui/.config/alacritty/alacritty.toml

@@ -0,0 +1,50 @@
+[general]
+import = ["theme.toml"]
+
+[window]
+
+opacity = 0.7
+
+padding.x = 25
+padding.y = 25
+
+decorations = "Full"
+decorations_theme_variant = "Dark"
+
+[font]
+size = 12.0
+
+[font.bold]
+family = "CaskaydiaCove Nerd Font Mono"
+style = "Bold"
+
+[font.bold_italic]
+family = "CaskaydiaCove Nerd Font Mono"
+style = "Bold Italic"
+
+[font.italic]
+family = "CaskaydiaCove Nerd Font Mono"
+style = "Italic"
+
+[font.normal]
+family = "CaskaydiaCove Nerd Font Mono"
+style = "Regular"
+# family = "Source Code Pro"
+# family = "Liberation Mono"
+
+[cursor]
+blink_interval = 400
+blink_timeout = 15
+
+[cursor.style]
+shape = "Block"
+blinking = "On"
+
+[keyboard]
+
+bindings = [
+	{ key = "J", mods = "Control|Shift", action = "ScrollLineDown" },
+	{ key = "K", mods = "Control|Shift", action = "ScrollLineUp" },
+	{ key = "D", mods = "Control|Shift", action = "ScrollPageDown" },
+	{ key = "U", mods = "Control|Shift", action = "ScrollPageUp" },
+]