docs(pi): full 'new machine' deploy recipe in extensions/pi/README

Consolidates the step-by-step recipe that's been living in diary entries
and session chat into the canonical pi bring-up doc. Covers:

  0. Prerequisites (zsh+oh-my-zsh, uv, tmux 3.2+, AWS creds)
  1. Dotfiles: myconfigs provision (tmux CSI-u, ~/.config/pi/.env, zsh loader)
  2. pi install (upstream brew/npm)
  3. mempalace CLI (uv tool install) + mempalace-toolkit install.sh
  4. pi settings bootstrap (start without --model, region prefix table)
  5. AWS env verification (git-crypt unlock gotcha)
  6. Opencode MCP registration pointer (if applicable)
  7. First run + wake-up injection smoke test
  + Verification checklist + uninstall

Root README.md adds a short summary box in the Setup section pointing at
the full recipe, so readers coming in from the front door find the pi
path immediately but the details stay with the files they install.

Covers: macOS + Linux. Works for homelab / work-macos / any myconfigs
profile that ships .config/pi/ + pi-env.zsh.

README.md

@@ -232,6 +232,29 @@ export PATH="$HOME/.local/bin:$PATH"
 
 **If `install.sh` reports `Skipping <name> — already exists`:** there's a leftover symlink or file at `~/.local/bin/<name>` from a previous install (e.g. the pre-split `cli_utils` days). The installer prints the exact `rm && ./install.sh` command to fix it — remove the stale entry and re-run. It will never clobber an existing file without the user explicitly removing it first.
 
+### Deploying pi on a new machine (full recipe)
+
+If the target machine also runs [pi](https://github.com/mariozechner/pi-coding-agent), there's a longer multi-step recipe covering dotfiles provisioning (tmux CSI-u keys, `~/.config/pi/.env`, zsh loader), mempalace install, pi settings bootstrap (starting pi without `--model`), and the AWS env verification. It lives in **[`extensions/pi/README.md` § Deploying pi on a new machine](extensions/pi/README.md#deploying-pi-on-a-new-machine)** so the step-by-step stays next to the files it installs.
+
+Quick summary:
+
+```bash
+# 1. Dotfiles (tmux extended-keys, ~/.config/pi/.env, pi-env.zsh)
+git clone <myconfigs> && cd myconfigs && ./provision.sh --profile <profile>
+
+# 2. pi (upstream)         3. mempalace CLI
+brew install pi-coding-agent    uv tool install mempalace
+
+# 4. This repo's install.sh
+cd ~/mempalace-toolkit && ./install.sh
+
+# 5. pi settings (one-time bootstrap, region-specific)
+cp extensions/pi/settings.example.json ~/.pi/agent/settings.json
+$EDITOR ~/.pi/agent/settings.json   # adjust eu./us./anthropic: prefix
+
+# 6. Open fresh shell, run `pi`. Wake-up auto-injection proves end-to-end.
+```
+
 ### First mine
 
 ```bash