golangci-lint v2 is reported clean: --out-format was removed and exit 3 is ignored #11

runGolangciLint in src/harness/check-engine/tool-runners/go.ts still runs golangci-lint run --out-format=json. That flag was removed in golangci-lint v2 (March 2025). v2 exits 3 with unknown flag: --out-format, and the runner treats exit codes 0, 3, and 4 as a clean run, so interlinked check --only golangci-lint reports zero findings and never reads the output.

On v1, exit 3 meant an analysis failure, and skipping it was intentional. On v2, exit 3 is also what a rejected flag produces, so the skip hides the broken invocation. The v2 replacement is golangci-lint run --output.json.path stdout (https://golangci-lint.run/product/migration-guide/#output).

Repro with golangci-lint v2.13.2:

$ golangci-lint run --out-format=json ./...
Error: unknown flag: --out-format
$ echo $?
3

$ interlinked check --only golangci-lint --json
{ "golangci-lint": { "count": 0, "findings": [] } }

That check finished in well under a second. The same tree, run with --output.json.path, reports a real typecheck issue.

Expected:

• Detect golangci-lint v2 and pass --output.json.path stdout (keep --out-format=json only for v1).
• Do not treat a flag-parse failure as a clean result. Surface a verdict such as "golangci-lint did not produce a verdict" instead of count: 0.