[hln33]

Description

Reverts #788 (commit 8bb88f56943ff322a5248f9d456c0be9dfedcb50) exactly.

The revert restores exporter version 0.0.1, beta/experimental status, and the SDK plugin payload experimental metadata. It restores the prior tests. It preserves unrelated changes and exporter runtime behavior.

Testing

Validated locally with Python 3.14.4 and Hatch 1.18.1.

• The committed patch exactly matches the inverse of the squash commit across all seven files.
• hatch run test:cov: 5,392 passed, two cloud tests skipped; 98% reported coverage.
• Focused plugin and telemetry suite: 265 passed, including both local telemetry end-to-end tests.
• Restored metadata test: passes with the revert and fails against the merged PR.
• hatch run types:check: passed all five configured groups.
• All nine packages passed hatch fmt --check and hatch build.
• Installed-wheel checks: current OTel 701 + 12 passed; legacy OTel 12 passed.
• Exporter wheel and sdist: version 0.0.1 and Beta metadata verified. Noneditable import and restored plugin metadata checks passed.
• Distribution legal files, OTel dependency contract, and commit lint passed.

No extra tests or conformance changes were added beyond the exact revert. Cloud execution and the Python 3.11–3.13 CI matrix have not run for this branch.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license.