Document the setup wizard

Co-Authored-By: Claude Opus 5.5 <[email protected]>

CLAUDE.md

@@ -98,8 +98,14 @@ modern stack.
   those). Uninstall run from inside the install relaunches from a `%TEMP%\t5de-uninstall-<pid>.exe` copy, which
   deletes itself afterwards; `-remove-data` also removes `HKCU\Software\T5DE` and `%APPDATA%\T5DE`. Reinstalling
   replaces the folder, including the browser profile (cookies). Verified end to end on a real install.
-  Still to do: the Wails UI (with modify/repair from the installed setup), embedding the bundle, release CI (tag
-  releases, a rolling nightly pre-release), code signing.
+  Done: `cmd/t5de-setup`, the wizard (Wails v2 with a plain HTML/CSS/JS `frontend/`, no npm; build tags `desktop,
+  production`, `-H=windowsgui`; Linux CI vets and cross-compiles it for Windows only). Modes: install; manage
+  (when an install exists, or run from the copy in one: change patches, repair/update, uninstall); uninstall (what
+  "Apps & features" runs). Run from inside an install, it relaunches from a temporary copy. Bundle: embedded from
+  `cmd/t5de-setup/bundle/manifest.json` (gitignored; copied in by release builds), else `-bundle`, else the
+  install's `t5de-bundle.json`. `T5DE_SETUP_SELFTEST=<file>` makes the page report what it rendered and close.
+  Logo and icon: `patcher/assets` (the user's). Still to do: the exe icon resource (go-winres `.syso`), release CI
+  (embed the bundle; tag releases, a rolling nightly pre-release), code signing.
 - Contributor setup: revisit a single bundled `t5de` executable once the Go patcher exists. Findings so far:
   `msiexec /a` extracts python.org's 2.7.18 MSI unelevated into a working portable Python 2.7 (tests pass with it),
   and contributors who have the pinned client installed could skip the installer download and 7-Zip.

README.md

@@ -93,6 +93,15 @@ go run ./cmd/t5de-patcher install -bundle ../build/bundle/manifest.json -desktop
 go run ./cmd/t5de-patcher uninstall
 ```
 
+`cmd/t5de-setup` is the same as a wizard (Wails, with a plain HTML/CSS/JS page in `frontend/`): install, and
+change, repair or uninstall an existing install. Release builds carry the bundle inside (copied to
+`cmd/t5de-setup/bundle/manifest.json` before building); in development pass it:
+
+```sh
+go build -tags desktop,production -ldflags "-H=windowsgui" -o t5de-setup.exe ./cmd/t5de-setup
+./t5de-setup.exe -bundle ../build/bundle/manifest.json
+```
+
 ## Tests
 
 ```sh