[Sync] adopt unified stow layout from the private repo

Mirrors the private dots tree at 900bdda: one shared base plus per-host
overlays, replacing the old flat .config/ layout (last synced 2026-06-28).

- packages: common/ gui/ wm/ lw/ fl/ + install.sh and bin/ tooling (dotsync,
  reconcile-hyde.sh)
- new README (layout, deploy order, HyDE dependency), plus ToDo.md and
  HYDE-UPDATE.md
- current HyDE waybar rig (layouts/, cava), pi agent extensions, claude/
  config, tmux, presenterm, aichat roles
- drops stale duplicates and generated cruft that should never have been
  tracked: the second top-level .pi/ copy, btop.log, zellij config.kdl.bak,
  fish_variables, nvim codecompanion.lua
- .pi/agent/auth.json is gitignored now; auth.json.example ships instead
- fl/ and wm/ hypr themes/ stay untracked (HyDE-generated per machine, per
  the root .gitignore)

gui/.config/waybar/modules/bluetooth.jsonc

@@ -0,0 +1,15 @@
+    "bluetooth": {
+        "format": "",
+        "rotate": ${r_deg},
+        "format-disabled": "",
+        "format-connected": " {num_connections}",
+        "format-connected-battery": "{icon} {num_connections}",
+        // "format-connected-battery": "{icon} {device_alias}-{device_battery_percentage}%",
+        "format-icons": ["󰥇", "󰤾", "󰤿", "󰥀", "󰥁", "󰥂", "󰥃", "󰥄", "󰥅", "󰥆", "󰥈"],
+        // "format-device-preference": [ "device1", "device2" ], // preference list deciding the displayed device If this config option is not defined or none of the devices in the list are connected, it will fall back to showing the last connected device.
+        "tooltip-format": "{controller_alias}\n{num_connections} connected",
+        "tooltip-format-connected": "{controller_alias}\n{num_connections} connected\n\n{device_enumerate}",
+        "tooltip-format-enumerate-connected": "{device_alias}",
+        "tooltip-format-enumerate-connected-battery": "{device_alias}\t{icon} {device_battery_percentage}%"
+    },
+