ccboard 0.11.1 needs a clean Homebrew web build path

[chenrui333]

Summary

ccboard 0.11.1 appears blocked on a non-Homebrew Rust WASM target prerequisite during the web asset build for PR #4837.

PR: #4837

Evidence

• The formula currently builds the frontend with:
  • cd crates/ccboard-web && trunk build --release
• Upstream documents the frontend build prerequisites as:
  • cargo install trunk
  • rustup target add wasm32-unknown-unknown
• Source references:
  • crates/ccboard-web/README.md
  • README.md web build section
• The release tarball does not ship the prebuilt crates/ccboard-web/dist/ assets, so the formula cannot skip the frontend build and still preserve the intended web functionality.
• CI currently fails on Linux builders for #4837:
  • build-formula (ubuntu-22.04, ...)
  • build-formula (ubuntu-22.04-arm, ...)

Why this is a blocker

Homebrew clean builders do not rely on ad-hoc rustup target add ... setup. If the frontend build really requires the wasm32-unknown-unknown target to exist ahead of time, this is not a normal formula-only fix without either:

1. upstream shipping the built web assets in the release tarball, or
2. upstream providing a source-build path that works in a clean Homebrew Rust toolchain without rustup state.

Suggested next step

Decide whether to:

• accept a reduced-functionality formula build that omits the web frontend, or
• keep the PR blocked until upstream provides a clean source-buildable frontend path for Homebrew.