feat: close SDK compose/runtime/preflight parity gaps

[unarbos]

Summary

• add SDK parity command surfaces:
  • agcli utils compose-call
  • agcli view runtime-api call
  • agcli utils validate-extrinsic-params
• wire new CLI enums and dispatch paths (ViewCommands::RuntimeApi, new UtilsCommands variants)
• implement handlers in src/cli/sdk_cmds.rs for dynamic call composition, runtime API querying, and extrinsic-parameter preflight validation
• add focused unit tests for JSON arg parsing and mortal-era validation rules
• flip the six P1 SDK matrix rows from GAP to COVERED_CLI_ONLY for async+sync compose_call, query_runtime_api, and validate_extrinsic_params

Verification

• SKIP_METADATA_FETCH=1 cargo check --bin agcli
• SKIP_METADATA_FETCH=1 cargo build --release --bin agcli
• SKIP_METADATA_FETCH=1 cargo test --lib sdk_cmds::tests:: -- --nocapture
• target/release/agcli utils compose-call --help
• target/release/agcli view runtime-api call --help
• target/release/agcli utils validate-extrinsic-params --help
• target/release/agcli utils validate-extrinsic-params --nonce 1 --era mortal --mortality-blocks 64 --tip 0.1 --output json

Notes

• This PR closes the requested Step 4c command-surface GAPs and updates matrix mappings accordingly.
• Runtime API calls are implemented via subxt dynamic runtime API payloads and return both raw SCALE hex and decoded values in JSON output.