Verifier tests

Live under crates/canopen-eds-verify/tests/.

Test Case: Verifier passes on matching EDS + dump pair TEST_0670
status: open
verifies: REQ_0780

Use the captured pair from crates/canopen-eds-verify/tests/fixtures/EPOS4/ (EDS file + matching epos4.dump.json), call verify(eds, dump), assert Ok(VerifyReport { matched: true, .. }).
Test Case: Verifier reports the differing field TEST_0671
status: open
verifies: REQ_0781

Synthetic mismatched pair: real EDS, mutated JSON dump altering the 0x1018:02 product_code field. The returned VerifyReport shall contain at least one Difference entry whose field is exactly "Identity.product_code" and whose eds / dump values match the originals.
Test Case: Verifier reuses canopen-eds parser TEST_0672
status: open
verifies: REQ_0782

White-box: cargo tree -p canopen-eds-verify lists canopen-eds as a direct dependency and does not list canopen-eds-codegen, canopen-eds-rt, taktora-connector-can, or socketcan anywhere in the graph.
Test Case: Verifier exit codes follow the documented matrix TEST_0673
status: open
verifies: REQ_0783

Spawn the verifier binary three times: matching pair (expect exit 0), mismatched pair (expect 1), unreadable JSON path (expect 2). Asserted via Command::status().code().
Test Case: Verifier rejects unknown schema version TEST_0674
status: open
verifies: REQ_0784

Fixture JSON dump with "schema": "taktora.canopen.sdo-dump.v2". The verifier shall reject the input with a parse error (exit code 2) before any field comparison runs.