[blainemotsinger]

Closes #93

What changed

The startup splash now shows only the app name and the build version:

chute
v9.9.9

Removed the [account] connecting to host... line and the press any key to skip
instruction, along with the now-unused splashConnecting helper.

Any key still dismisses the splash (and is consumed, so q skips rather than quits);
only the on-screen messaging is gone.

Tests

tui/splash_test.go:

• TestSplashShowsOnlyNameAndBuild — exactly two content lines, chute and v9.9.9.
• TestSplashShowsDevWhenTheBuildHasNoVersion — an unversioned build renders dev.
• The splash-end tests now start from a real splash model and assert m.splash
  rather than a string that no longer exists.

Verification

gofmt -l . empty, go vet ./... clean, go test -count=1 ./... and -race pass;
coverage tui 91.2 (floor 89.1) / config 91.0 / mail 87.4 / main 38.8;
golangci-lint v2.15.0 0 issues.