fix(nesdoctor): cmd re-parsed the submit URL and destroyed every Windows result

Two submissions arrived carrying `v=0.2.0` and nothing else. Flagged from the
channel, not caught by us.

The Windows arm of `open_in_browser` was `cmd /C start "" <url>`. `cmd.exe`
re-parses its own command line and treats `&` as a command separator; Rust's
`Command` quotes arguments for the MSVC C runtime convention, which `cmd` does
not honour. So the URL was cut at its first `&` -- which in ours falls
immediately after `v=` -- and the browser opened

    https://doctor.nestri.io/?v=0.2.0

carrying nothing whatsoever. Reproduced exactly with the same mechanism in a
POSIX shell: `sh -c 'echo <url>'` unquoted prints precisely that prefix.

Every Windows user who pressed Enter lost their entire report, and lost it
silently -- the page returned 200 and thanked them. Windows is most of this
audience, so most of the data we would ever have collected was going to
disappear this way.

Now `rundll32 url.dll,FileProtocolHandler`, which hands the URL to the shell's
protocol handler with no command interpreter anywhere in the path, so nothing
re-parses it. `explorer.exe` also opens URLs and was rejected: it returns a
non-zero exit status even on success, which would make the caller believe it
had failed and fall through.

The relay now also refuses to thank anyone for a version-only arrival, since an
older binary keeps producing them and a URL pasted into a shell unquoted does
the same thing.

Version to 0.2.1.

Cargo.lock

@@ -2462,7 +2462,7 @@ dependencies = [
 
 [[package]]
 name = "nesdoctor"
-version = "0.2.0"
+version = "0.2.1"
 dependencies = [
  "anyhow",
  "clap",