Two byte-equivalence bugs caught by cross-runtime parity check:
1. _blake3() was falling back to BLAKE2b when hashlib lacked BLAKE3 (it
always does on stock CPython). Wallet addresses depend on the SAME
hash across all five brain runtimes. Required the `blake3` pip
package; no fallback. Python addresses now match the TS canonical
(@noble/hashes/blake3): encode_address(32x0x00) → "hanzo:UFC8qCW8...".
2. render_vtt joined lines with "\n" and appended one "" at the end,
producing a single trailing newline. Every other runtime emits "\n\n"
after each segment so cues are separated by a blank line per WebVTT
spec. Switched to explicit f-string append; render_srt fixed the same
way.
53 tests still pass.
zeekay
262593f4ec