feat(bootstrap): ternary weight packer/unpacker for packed-trit BRAM format (Wave 44, R-HT-1) #797

Wave 44 — R-HT-1: Ternary weight packer/unpacker

Summary

Add a host-side ternary weight packer/unpacker that converts between human-readable trit arrays [-1, 0, +1] and the 54-bit packed-trit format used by the W36a weight BRAM (27 trits × 2 bits/trit = 54 bits per word). This bridges the spec-level ternary encoding with the hardware format and enables realistic weight generation for the InferenceEngine.

Scope

• bootstrap/src/host/ternary.rs — new file
• bootstrap/src/host/mod.rs — add pub mod ternary + re-exports
• bootstrap/src/main.rs — new CLI subcommand host-pack + host-unpack
• bootstrap/tests/host_ternary.rs — >= 20 integration tests
• docs/NOW.md — wave-44 entry

Constraints

• Bootstrap-only — L2/L6 clean
• Encoding: 2'b00 = -1, 2'b01 = 0, 2'b10 = +1 (matching trit_stdlib.rs)
• 27 trits per 54-bit word, LSB-first
• No new dependencies

Acceptance

• pack_words() and unpack_words() round-trip correctly
• CLI commands host-pack and host-unpack
• >= 20 integration tests
• docs/NOW.md updated
• Zero regressions