0.4.0 — the reference BCI

Added

• The reference BCI (cargo run --locked --release --bin reference_bci).
  One chain from synthetic EEG to application intent with the consent
  boundary in the middle: axonos-hal → axonos-signal-pipeline →
  axonos-supervisor → axonos-vault for derived data and axonos-consent's
  publication gate for intents, delivered as axonos-sdk types. A signed
  withdrawal at frame 9 000 stops both channels from that frame; malformed,
  forged, replayed and re-granting consent frames are refused as the
  specification requires. The binary verifies zero post-withdrawal leakage,
  the gate and vault counts against what the application received, and the
  accounting identity, then replays the whole session and compares SHA-256
  digests of the raw input, the application's input and the event trace.
  --json prints the same run in machine-readable form; the exit code is the
  verdict.
• reference/reference-bci-7.txt (FIELD) and
  reference/reference-bci-7-clean.txt (CLEAN), diffed byte for byte in CI.
• 18 tests: granted, withdrawn before the first frame, withdrawn mid-session,
  every malformed frame shape, replay, hash reproducibility, the two
  transcripts, the JSON report, a 100 000-frame session, argument checking —
  and two deliberate defects (publishing without the gate, withdrawing without
  revoking the grant) that the verifier must catch.
• Dependencies: axonos-consent v0.9.2 and axonos-sdk v0.3.5, pinned by tag
  and watched by verify_pins.py; ed25519-dalek to sign the simulated
  trusted path and sha2 for the digests, both already in the graph through
  axonos-consent.

Found

• A withdrawal stopped half the system. Nothing in the organisation
  connected a consent withdrawal to a vault grant, so derived data would have
  kept flowing under a live grant after intents stopped. The reference BCI
  revokes the grant in the same step and keeps the unconnected version as a
  failing test.
• One refusal, two numbers. axonos-consent documents the suppression
  codes the SDK delivers as 0x05/0x06; axonos-sdk numbers the same
  errors 0x0301/0x0302. Mapped by variant here; not reconciled.

Changed

• rust-version is 1.85, the floor axonos-consent and axonos-sdk declare.

Fixed

• The README's organ table listed pins three releases old (hal v0.2.0,
  vault v0.2.0, supervisor v0.1.1) and its heading still said three organs.
  CITATION.cff still said 0.3.2. All now match Cargo.toml.
• A compiled scripts/__pycache__/verify_pins.cpython-312.pyc had been
  committed. Removed, and __pycache__/ is ignored.
• SPDX licence and copyright headers on every source file.

No timing is measured by anything in this release. The 972 µs both binaries
print is the response time axonos-hal admits configurations against.