ci(nightly): keep the legacy binary name out of nightly.yml

`.github/scripts/release-workflows.test.js:105` asserts
`doesNotMatch(nightly, /codewhale-tui/)`. The surrounding assertions show why:
nightly must build `-p codewhale-cli` and stage `codewhale`/`codew` artifacts,
never the legacy `codewhale-tui` binary. It is a textual guard, so prose trips
it as readily as a build argument would.

The stack-size comment I added named the crate being compiled. Reworded to
`crates/tui`, which says the same thing without the guarded token. The
underscored `codewhale_tui` in the quoted rustc error is untouched — the guard
matches the hyphenated binary name, and the quoted diagnostic is the evidence
that makes the comment worth having.

Weakening the guard to accommodate a comment would have been the wrong trade:
it protects a real invariant about what nightly builds.

Verified: the full ci.yml `versions` job run locally — check-versions.sh plus
all thirteen release-helper contract tests — passes end to end, and
actionlint 1.7.12 is clean.

Signed-off-by: Hunter Bown <[email protected]>

.github/workflows/nightly.yml

@@ -115,7 +115,7 @@ jobs:
         # RUST_MIN_STACK sizes the stack of the LLVM worker threads rustc
         # spawns to run `optimize module <crate>-cgu.N`. With `lto=off` the
         # per-CGU optimization pipeline runs while the *library* is compiled
-        # rather than being deferred to the ThinLTO stage, and one codewhale-tui
+        # rather than being deferred to the ThinLTO stage, and one crates/tui
         # codegen unit needs more stack than a 1 MiB thread provides. Measured
         # on aarch64 by holding the crate and every flag fixed and varying only
         # this value: 1 MiB crashes rustc, 2 MiB and 4 MiB succeed. Unix std