fix: repair CI after soroban-sdk 22.0.0 upgrade

[misrasamuelisiguzor-oss]

Summary

Every push/PR has failed all CI checks (Test, Lint, Format, WASM Build, Contract Size, Deny, Pre-commit, Coverage) for about the last 6 days, since the soroban-sdk 22.0.0 dependency bump merged without the fallout being fixed. This PR repairs the full chain:

• Dependency conflict: derive_arbitrary =1.4.2 vs soroban-sdk 22's ~1.3.0 requirement — dropped the unused pin
• compliance-client: compliance dep was dev-dependencies-only but used unconditionally in src/lib.rs (unresolved import on real builds) — moved to [dependencies]
• soroban-sdk 22 breaking change: u8 no longer implements TryFromVal — switched compliance tier fields to u32
• Syntax error left over from a partial edit in treasury/src/lib.rs
• Test suite updated for signature changes introduced alongside the SDK bump (create_invoice, mark_paid, treasury.initialize, raise_dispute, block_address)
• soroban-sdk 22 testutils behavior change: events no longer accumulate across separate top-level calls (fixed assertions to check per-call), and nested require_auth() inside cross-contract calls now needs mock_all_auths_allowing_non_root_auth()
• Real bug fix: batch_create_invoice didn't reject duplicate merchant nonces within the same batch, only against existing storage
• Stale test expectations: rotation approval-weight assertion and a cancel-settlement panic message string that no longer matched contract behavior
• CI workflow bug: build.yml was missing the required toolchain input for dtolnay/rust-toolchain@master, causing an immediate failure before checkout even completed
• WASM build: all three contract crates defaulted to the testutils feature, which pulls in std/serde_json/rand and breaks wasm32-unknown-unknown release builds; removed the default and added a size-optimized [profile.release] so treasury (the largest contract, ~62.6KB) fits under the 64KB contract-size limit

Test plan

• cargo check --workspace clean
• cargo test --workspace — all suites pass
• cargo fmt --all -- --check clean
• cargo clippy --workspace -- -D warnings clean
• cargo build --target wasm32-unknown-unknown --release for all 3 contracts, all under the 64KB size limit
• pre-commit run --all-files passes
• Verified cargo-deny license/advisory results manually (sandbox couldn't complete the advisory-db clone, but all new transitive deps use already-allowed licenses)

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