[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)

lw/.pi/agent/settings.json

@@ -0,0 +1,37 @@
+{
+  "defaultProvider": "duskadiy",
+  "defaultModel": "gemma-4-26B-A4B-it-UD-IQ4_XS",
+  "defaultThinkingLevel": "off",
+  "theme": "catppuccin-mocha",
+  "quietStartup": false,
+  "defaultProjectTrust": "ask",
+  "enableInstallTelemetry": false,
+  "enabledModels": [
+    "lwcpp/*",
+    "localcpp/*",
+    "duskadiy/*"
+  ],
+  "compaction": {
+    "enabled": true,
+    "reserveTokens": 6144,
+    "keepRecentTokens": 6000
+  },
+  "retry": {
+    "enabled": true,
+    "maxRetries": 3,
+    "baseDelayMs": 2000,
+    "provider": {
+      "timeoutMs": 3600000
+    }
+  },
+  "httpIdleTimeoutMs": 600000,
+  "npmCommand": [
+    "fnm",
+    "exec",
+    "--using=22",
+    "--",
+    "npm"
+  ],
+  "showHardwareCursor": true,
+  "lastChangelogVersion": "0.83.0"
+}