fix(note): check spent nullifiers during transport import

[wodesiku]

What does this PR do?

Marks note-transport imports as ConsumedExternal when their nullifiers were already committed on-chain before the client imported them.

Related Issue

Fixes #2422

Root Cause

Notes delivered through the note transport enter import_note_records_by_details via NoteFile::ExpectedNote. That path discovers and authenticates the note commitment, but it did not query historical nullifier state. The existing get_nullifier_commit_heights check was only used by the inclusion-proof import path.

When a restored client has already synced past a note's spend block, forward nullifier sync starts after the checkpoint and can never observe that historical spend. The transport-imported record therefore remained Committed and was returned as consumable even though the node would reject it as already spent.

Changes Made

• Batch nullifier lookups for notes found committed during details import.
• Start the lookup at the earliest imported note inclusion block so historical spends are included.
• Reuse the existing InputNoteRecord::consumed_externally state transition.
• Add a transport regression test covering a private note consumed on-chain before its first NTL delivery.
• Leave notes that are still only Expected unchanged and avoid an RPC call when no committed details are found.

How to Test

Command attempted:

cargo test --locked -p miden-client-unit-tests fetch_private_notes_marks_historically_consumed_note -- --nocapture

The test was blocked before compilation by the Windows environment while building the existing miden-node-proto-build v0.16.0-rc.1 dependency:

file '...miden-node-proto-build-0.16.0-rc.1\proto
emote_prover.proto' is not in any include path

cargo check --locked -p miden-client --features testing hit the same pre-test build-script failure. WSL Ubuntu-22.04 is installed but has no Cargo toolchain. No test assertion failure was observed.

Scope

• No new dependencies.
• Cargo.lock unchanged.
• Focused to note import behavior and its transport integration test.

[igamigo]

Thanks! This is already covered by #2438 (which will do a bit more than this), so closing this PR for now.