The language, its compiler and CLI (compiler/, written in brine), the C
runtime, docs, examples and tests. The compiler builds itself; the seed in
bootstrap/brinec.c (its own generated C) builds it from scratch with only a
C compiler. The original Rust bootstrap compiler is retired.

Also in this version:
- the prover only uses the parts of each fact that are connected to the
  goal (plus the conditions that select a branch), and its search budget
  now counts every case: checking the compiler went from 23 s to 0.6 s
  with no proofs lost
- os.exe_path() and os.set_cwd(); `brine test` sets $BRINE for tests
- fmt: f-strings no longer make the formatter give up on a file, and its
  fallback keeps the final newline
- tests/integration.br replaces the Rust test suite

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