refactor(test): clean up duplicated e2e test structure

- Remove nested framework/ directory with duplicated content
- Keep flat structure in acp/test/e2e/ with framework.go at root
- Keep comprehensive getting_started tests (857 lines)
- Remove redundant MCP transport tests
- All unit and e2e tests pass

Following delete-more-than-add principle - removed 6 duplicate files.

Author: dexhorthy