[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/clock.jsonc

@@ -0,0 +1,25 @@
+    "clock": {
+        "format": "{:%H:%M}",
+        "rotate": ${r_deg},
+        "format-alt": "{:%R 󰃭 %d·%m·%y}",
+        "tooltip-format": "<span>{calendar}</span>",
+        "calendar": {
+            "mode": "month",
+            "mode-mon-col": 3,
+            "on-scroll": 1,
+            "on-click-right": "mode",
+            "format": {
+                "months": "<span color='#ffead3'><b>{}</b></span>",
+                "weekdays": "<span color='#ffcc66'><b>{}</b></span>",
+                "today": "<span color='#ff6699'><b>{}</b></span>"
+            }
+        },
+        "actions": {
+            "on-click-right": "mode",
+            "on-click-forward": "tz_up",
+            "on-click-backward": "tz_down",
+            "on-scroll-up": "shift_up",
+            "on-scroll-down": "shift_down"
+        }
+    },
+