release: prepare v1.0.0-beta.8

[pablormier]

Summary

Promotes the current dev branch to main for the CORNETO
v1.0.0-beta.8 release.

Highlights

• Add optional AnnNet interoperability:
  • convert CORNETO graphs and directed hypergraphs to AnnNet;
  • convert flat AnnNet graphs back to CORNETO;
  • preserve parallel edges, endpoint coefficients and ordinary attributes;
  • document intentionally unsupported or lossy edge cases.
• Improve GPR parsing performance and robustness.
• Fix multi-sample FBA bounds, objective naming and indicator handling.
• Improve multi-condition iMAT performance and documentation.
• Fix acyclic-flow ordering and add small-graph regression coverage.
• Fix CarnivalFlow BFS handling of sample input vertices.
• Add FBA, multi-sample FBA, iMAT and plotting examples.
• Allow the guarded release helper to target an explicit publication remote.

Validation

• 410 tests passed.
• 35 tests skipped because their optional dependencies or environments were unavailable.
• Ruff linting and formatting checks passed.
• Full Sphinx documentation build completed successfully.
• The release helper passed an isolated end-to-end --remote public --dry-run.

Release process

After merging this PR:

poetry run release v1.0.0-beta.8 --remote public --dry-run
poetry run release v1.0.0-beta.8 --remote public