Test companionCapGrantRules, sourcesHaveWildcard, sourcesHaveDangerAll, srcIPsWithRoutes, the FilterAllowAll fix for grant-only policies, compileViaGrant, compileGrantWithAutogroupSelf grant paths, and destinationsToNetPortRange autogroup:internet skipping. 51 subtests across 8 test functions covering all grant-specific code paths in filter.go that previously had no test coverage. Updates #2180