test: cover monotonic escrow id allocation

[meteop-x]

Summary

• adds regression coverage for escrow IDs starting at 1 and increasing through 10 successful create_escrow calls
• verifies each generated escrow remains pending and is stored with the expected seller/resolver/token/amount/window
• applies rustfmt to the touched escrow contract files

Closes #29

Verification

• cargo fmt -p trustlink-escrow -- --check
• cargo test -p trustlink-escrow -- --nocapture (10 passed)

[JSE19]

👋 main has been fixed — \und_escrow\ and
aise_dispute\ are restored and clippy is clean. Could you rebase your branch on the latest main so CI re-runs? \git rebase main\ then force-push.