feat(cli): bounty + contract commands (chain v0.4.0)

[proofmancer]

Summary

Adds CLI commands to create + query bounties and contracts (the chain v0.4.0 marketplace), mirroring the existing attestation command pattern (resolve_signer → build RuntimeCall → build_sign_submit). Pins the chain crates to v0.4.0 and syncs the constants manifest so the newly-compiled bounty + contract module macros resolve.

• ligate bounty (src/bounty.rs): post / claim / dispute / resolve / cancel / finalise → RuntimeCall::Bounty(..). post parses an --acceptance predicate (any / attestor-set:<las1…> / payload-hashes:<lph1…>,… / peer-count:<n>).
• ligate contract (src/contract.rs): post / commit / deliver / accept / reject / resolve / cancel / finalize → RuntimeCall::Contracts(..) (plural variant, matching the Contracts module struct). Reuses the 32-byte hex parser for --criteria-doc-hash + --commit-hash.
• ligate query (src/query.rs): adds bounty / dispute / contract / delivery / contract-dispute read subcommands hitting the chain REST routes (/modules/bounty/..., /modules/contracts/...).
• Cargo.toml: chain deps → v0.4.0; new bounty + contract git deps (native); package 0.2.x → 0.3.0. SDK fork revs unchanged (v0.4.0 keeps v0.3.0's pins).
• constants.toml: synced verbatim to ligate-chain's v0.4.0 manifest — adds BOUNTY_DISCRIMINANT = 22 + CONTRACTS_DISCRIMINANT = 23 (resolved via the existing CONSTANTS_MANIFEST_PATH env var in CI). This is the same stale-manifest break that hit ligate-api.

Constants-manifest sync

Bumping to v0.4.0 + adding the bounty/contract deps means the CLI now transitively compiles the bounty + contract chain crates, whose impl_hash32_type! / module macros require BOUNTY_DISCRIMINANT (22) and CONTRACTS_DISCRIMINANT (23). The CLI keeps its own constants.toml at the repo root, resolved by CONSTANTS_MANIFEST_PATH (set in .github/workflows/ci.yml + release.yml). Fixed by cp ligate-chain/constants.toml over the CLI copy; both discriminants confirmed present.

Test plan

• cargo build --release --bin ligate compiles (with SKIP_GUEST_BUILD=1 RISC0_SKIP_BUILD_KERNELS=1 + libclang env)
• cargo clippy --all-targets -- -D warnings clean
• cargo fmt --all -- --check clean
• cargo test --bin ligate — 24/24 pass (7 new: acceptance-predicate + hash32 parsers)
• ligate --version → v0.3.0; bounty / contract / query subcommand trees + --ground / --decision value-enums parse correctly (per-module variants distinct)
• Live posting deferred — needs a funded signing key (no real txs submitted from this branch)