[fly1d]

FLAG_IGNORE_SLICE_ORDER can return more than MaxDiff differences: with the default limit of 10, two disjoint eight-element slices return 16.

Apply the budget in the value-count loop so both passes share the limit, including differences already found in earlier fields. Keep the existing zero-diff behavior for zero and negative limits, as requested in review. This follow-up changes one guard and the two nonpositive test expectations; the positive-limit, ordering and multiplicity controls remain unchanged.

Validation on Go 1.26.6, macOS arm64:

• The same final 11-case fixture gives two nonpositive failures and nine passing controls on the previous PR head, then 11/11 with the repair.
• Full go test ./..., go test -race ./..., go vet ./..., formatting and diff checks pass. Tests use existing tools with dependency/toolchain downloads disabled.
• Main's separate complex-comparison change was checked for exact patch composition; no mechanical sync or combined-main runtime result is claimed.

The existing Go workflow filters master while this PR targets main; these are local results, not a hosted Go/platform-matrix result.