Find go.mod files that could not be fully resolved offline

Find go.mod files whose module graph did not fully resolve at parse time, so GoModTidy skipped adding and removing requirements. The offline no-op is safe but silent, making a module that badly needs tidying look identical to one already tidy. This recipe marks such go.mod files and records a data table naming the module, its resolution status, the unresolved imports, and the toolchain failure reason, so a run can be triaged and re-run once the modules resolve. It reports only and does not modify the go.mod.