[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/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",
+      },
+    },
+  },
+}