test: cover register_service_with_metadata atomicity and svc_reg event

[yunus-dev-codecrafter]

closes #100

test: cover register_service_with_metadata atomicity and svc_reg event

Summary

Adds the missing register_service_with_metadata entrypoint and comprehensive
test coverage for the atomic registration-plus-metadata operation.

Changes

contracts/escrow/src/lib.rs — new entrypoint

Created register_service_with_metadata(env, service_id, description, owner):

• Calls ensure_not_paused — rejects calls while paused (panics Emit structured events on admin, price, and registration state changes #4).
• Calls require_admin — only the contract admin may call.
• Sets ServiceRegistered(service_id) = true.
• Persists ServiceMetadata(service_id) with the provided description and owner.
• Emits svc_reg(service_id, owner) for indexers.

Also applied cargo fmt fixes to resolve_dispute (pre-existing formatting drift).

contracts/escrow/src/test.rs — 7 new tests

Test	Coverage
test_register_service_with_metadata_sets_both_slots	After one call, is_service_registered is true and get_service_metadata returns the exact description + owner.
test_register_service_with_metadata_emits_svc_reg_event	svc_reg(service_id, owner) event is emitted via env.events().all().
test_register_service_with_metadata_idempotent_overwrite	Re-registering an existing id overwrites its metadata (owner and description).
test_register_service_with_metadata_empty_description	An empty String description is accepted.
test_register_service_with_metadata_rejects_non_admin	#[should_panic] — non-admin caller is rejected.
test_register_service_with_metadata_panics_when_paused	#[should_panic(expected = "Error(Contract, #4)")] — pause gate honoured.
test_register_service_with_metadata_equivalent_to_separate_calls	Combined call produces identical storage state to register_service + set_service_metadata sequence.

Also fixed 17 pre-existing client.settle(&admin, &agent, &svc) calls — the
Soroban SDK 22.0 client generator strips env from entrypoint arguments, so
settle(env, agent, service_id) produces a 2-arg client method
settle(&self, agent, service_id).

Test output

running 7 tests
test test_register_service_with_metadata_idempotent_overwrite ... ok
test test_register_service_with_metadata_empty_description ... ok
test test_register_service_with_metadata_emits_svc_reg_event ... ok
test test_register_service_with_metadata_equivalent_to_separate_calls ... ok
test test_register_service_with_metadata_panics_when_paused - should panic ... ok
test test_register_service_with_metadata_rejects_non_admin - should panic ... ok
test test_register_service_with_metadata_sets_both_slots ... ok

test result: ok. 7 passed; 0 failed; 0 ignored; 0 measured; 179 filtered out; finished in 0.23s

Security notes

• Registration and metadata land together: Both ServiceRegistered and
  ServiceMetadata are written in a single call; there is no window where
  a service is registered but has no metadata (or vice versa).
• Only admin can call: require_admin gates the entrypoint; non-admin
  callers are rejected with a panic.
• Pause gate respected: ensure_not_paused is checked before any state
  mutation, preventing calls while the contract is paused.
• Idempotent: Re-registering an existing service id overwrites metadata
  without side effects; empty descriptions are accepted.

[mikewheeleer]

solid — merging now