Desktop client (warp-desktop) with Wails v3

apps/desktop is the web client in a native window. It embeds the same
build warp-web does and serves it through the same Go package, so every
screen is shared. Unlike warp-web it proxies nothing: the client calls the
homeserver directly, and the CSP allows the homeserver plus any https:
and wss: origin for the call backend.

- First run asks for the homeserver: a server name or address, with
  .well-known discovery and a /versions check; File > Change homeserver
  asks again. Signed-in sessions keep their own base URL, so a change
  never sends one server's token to another.
- Links to other sites open in the system browser (/_desktop/links.js,
  added to index.html); only http, https and mailto are opened.
- One instance at a time, since sessions and keys live in the webview's
  storage.
- Dev builds open the DevTools Protocol on Windows when
  WARP_DESKTOP_REMOTE_DEBUGGING_PORT is set, for scripted testing.
- Packaging: icon, version info and manifest in the Windows exe, a macOS
  .app with camera and microphone descriptions, Linux packages via nfpm.
  Make targets: desktop, desktop-run, desktop-test, desktop-resources,
  desktop-macos, desktop-linux.

Web client: host and client move out of internal/ so the desktop app can
import them, and host gains AnyCallOrigin. The Dockerfile, .dockerignore
and the vite output path follow the move.

Pinned to Wails v3.0.0-beta.27.

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

apps/web/Dockerfile

@@ -26,8 +26,9 @@ FROM golang:1.26-alpine AS build
 WORKDIR /src/apps/web
 COPY apps/web/go.mod ./
 COPY apps/web/cmd ./cmd
-COPY apps/web/internal ./internal
-COPY --from=web /src/apps/web/internal/client/build/dist ./internal/client/build/dist
+COPY apps/web/host ./host
+COPY apps/web/client/client.go ./client/
+COPY --from=web /src/apps/web/client/build/dist ./client/build/dist
 
 ARG VERSION=0.0.0-dev
 ENV CGO_ENABLED=0 GOWORK=off