fixed minor fac rocket divergence

[markleader]

Summary

Align FAC rocket chamber-closure behavior in RocketSolver_solve_fac with legacy CEA2 semantics and stabilize cross-platform test expectations for Example 9 / FAC outputs.

Changes

• Updated FAC chamber-closure iteration logic in source/rocket.f90:
  • Switched Option-1 pressure correction direction to legacy-consistent form (pc / p_inj_check).
  • Normalized Option-1 convergence check using assigned injector pressure semantics.
  • Replaced fixed 4-pass outer loop with tolerance-driven iteration.
  • Added bounded safety guard (max_iter_chamber = 100) with warning on non-convergence.
  • Reseeded FAC combustor-end iterate each chamber iteration from current infinity state.
• Relaxed/standardized pFUnit FAC rocket tolerances to reflect expected solver deltas and improve robustness across compilers/platforms in source/rocket_test.pf.

Testing

• ctest -R cea_core_test
• python test_main.py
• python -m pytest

Compatibility / Numerical behavior

• No expected changes to numerical results
• Expected changes (explain and provide validation)

FAC rocket numerical results are expected to shift slightly due to chamber-closure iteration/parity fixes. Validation is covered by updated pFUnit rocket checks and Python RP-1311 Example 9 FAC assertions with adjusted tolerances.