* fix(txt-registry): skip creation of already-existing TXT records (#4914)
* refactor(registry): store existing TXT records temporarily between Records and ApplyChanges
* refactor: apply review suggestion for code cleanup
* test: add coverage for recreating A/CNAME records when TXT exists
* refactor: extract generateTXTRecordWithFilter to avoid redundant filtering
* test: add comprehensive test cases and isolate test data for t.Parallel
* docs: clarify comment for isNotManaged to reflect actual behavior
* fix: apply SetIdentifier before filtering TXT records, add regression test
* chore: fix lint warnings
* refactor: use key struct instead of concatenated string for map keys to reduce memory usage
* fix txt_test.go
* fix txt_test.go dependency
* refactor(registry/txt): rename to isAbsent