[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)

common/.config/nvim/lua/configs/lazy.lua

@@ -0,0 +1,47 @@
+return {
+  defaults = { lazy = true },
+  install = { colorscheme = { "nvchad" } },
+
+  ui = {
+    icons = {
+      ft = "",
+      lazy = "󰂠 ",
+      loaded = "",
+      not_loaded = "",
+    },
+  },
+
+  performance = {
+    rtp = {
+      disabled_plugins = {
+        "2html_plugin",
+        "tohtml",
+        "getscript",
+        "getscriptPlugin",
+        "gzip",
+        "logipat",
+        "netrw",
+        "netrwPlugin",
+        "netrwSettings",
+        "netrwFileHandlers",
+        "matchit",
+        "tar",
+        "tarPlugin",
+        "rrhelper",
+        "spellfile_plugin",
+        "vimball",
+        "vimballPlugin",
+        "zip",
+        "zipPlugin",
+        "tutor",
+        "rplugin",
+        "syntax",
+        "synmenu",
+        "optwin",
+        "compiler",
+        "bugreport",
+        "ftplugin",
+      },
+    },
+  },
+}