feat(storage): add targeted invoice TTL extension

[ZaaK0913-coder]

Closes #1723

Summary

• Add an admin-only extend_invoice_ttl entrypoint for a single invoice record set.
• Refresh the invoice record plus associated bid, investment, escrow, payment, and audit storage keys using existing TTL constants/helpers.
• Extend ExtendReport with payment/audit counts and emit ttl_extended events for each non-zero targeted kind.
• Add focused maintenance tests for unknown invoices, non-admin rejection, invoice-only refresh, and a populated record set.

Validation

• rustfmt --edition 2021 passed for touched implementation/test files that can be formatted independently.
• cargo fmt --all is currently blocked by a pre-existing parse error in quicklendx-contracts/src/test_bid_capacity_stress.rs:287 (unexpected closing delimiter).
• cargo test -p quicklendx-contracts extend_invoice_ttl -- --nocapture was attempted locally after installing a temporary Rust toolchain under D:\Programs\Rust; the build is blocked by existing crate baseline errors before these tests can run, including duplicate bench module registration, duplicate profits::compute_yield, unresolved idempotency / address_summary modules, and a missing InvalidLedgerSequence match arm in errors.rs.