fix: bring the docs in line with the no-admin route (release review)

Name the real trigger and CODEMAN_NO_ADMIN=0 in the READMEs and the
Installation page, add the install without git to the update tables and the
updater notes, record the installer's downloads in the supply chain section,
and say that the data directory question also removes a kept runtime.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/wiki/Installation.md

@@ -122,6 +122,14 @@ This route is taken by itself when `sudo` is not installed, when the account is
 `CODEMAN_NO_ADMIN=0` switches the detection off. Nothing on this route runs `sudo`,
 Homebrew or the Xcode tools installer.
 
+The group check cannot see a sudoers entry, so an account that sudoers lists by name, with
+a password, takes this route too. The summary then reads `could not confirm that this
+account may use sudo`, and to use `sudo` anyway:
+
+```bash
+curl -fsSL https://getcodeman.com/install | CODEMAN_NO_ADMIN=0 bash
+```
+
 What to know about it:
 
 - **Linux needs make, a C++ compiler and python3 to be there already.** node-pty compiles
@@ -279,8 +287,10 @@ npm uninstall -g aicodeman      # npm route
 
 The installer route asks before it removes `~/.codeman/runtime` (the Node.js and tmux it
 downloaded, if any), and keeps it by default when you installed CLIs there with
-`npm install -g`. Neither removes `~/.codeman/` or `~/codeman-cases/`. Delete those by hand if you want the
-state and your case folders gone as well, and check `~/codeman-cases/` first: linked cases
+`npm install -g`. That folder is inside `~/.codeman/`, so saying yes to the data directory
+question that follows removes it even if you kept it a step earlier, and the question says
+so. By default neither route removes `~/.codeman/` or `~/codeman-cases/`. Delete those by hand
+if you want the state and your case folders gone as well, and check `~/codeman-cases/` first: linked cases
 point at directories you already had, but cases created from scratch have their only copy
 there.