release: 0.3.0

[zy0n]

Cuts 0.3.0 — aligns the client with RAILGUN firmware 1.6.1 (clear-sign-v1). Minor bump: contains a breaking, firmware-coordinated change.

Breaking

• Spending-public-key retrieval now targets firmware ≥ 1.6.1 (P1 = 0x01, display + confirm). getPublicKey() / getWalletArtifacts() now require an on-device confirmation, and older firmware rejects the fetch.

Added

• Viewing public key (INS 0x10) and RAILGUN address (INS 0x14) device accessors.
• CLEAR_SIGN transact protocol builders (INS 0x11, experimental) + shape validator + FINALIZE parser.
• Fully customizable, chain-scoped EIP-7702 derivation path (account/chainId/ephemeralIndex), with a chain-scoping guard.
• Capability flags + CAPABILITY_STATUS.clearSign.

Changed

• Bundled SCP install artifacts updated to the firmware 1.6.1 clear-sign-v1 build (flex + Nano S Plus).

Version bump, CHANGELOG, and install pins (#v0.3.0 + tarball URL) only — the underlying code is already on main (#22–#25) and device-verified. Full suite green.

After merge: push main → release to fire the Release workflow (packs, tags v0.3.0, creates the GitHub Release + tarball).