FWPH: forward linearize_* so the can't-linearize warning fires (#274)

[DLWoodruff]

Summary

• Fixes FWPH does not warn that it can't linearize the objective #274. The vanilla fwph_hub / fwph_spoke factories did not forward cfg.linearize_proximal_terms or cfg.linearize_binary_proximal_terms into the options dict handed to FWPH, so FWPH._options_checks_fw never saw the flag and the user got no warning when they combined --linearize-proximal-terms with --fwph. With an LP-only solver (e.g. glpk) optimization silently proceeded and then failed in the QP solve, exactly as Matthew-Signorotti reported.
• cfg_vanilla.fwph_hub and cfg_vanilla.fwph_spoke now explicitly set options["linearize_proximal_terms"] and options["linearize_binary_proximal_terms"] after the _fwph_options merge, mirroring the existing pattern in ph_hub.
• opt/fwph.py _options_checks_fw: gate the two warning prints on self.cylinder_rank == 0 so HPC runs don't emit N copies of the same message.
• New tests in mpisppy/tests/test_config.py cover both the cfg_vanilla forwarding and the rank-0 warning paths in FWPH._options_checks_fw.

Note: bknueven's follow-up suggestion (FWPH should accept separate mip_solver_name / qp_solver_name so you can pair glpk/cbc with ipopt) is tracked as a separate enhancement in #712.

Test plan

• ruff check clean on changed files
• Manual reproduction with mpiexec -np 2 ... --fwph --linearize-proximal-terms --solver-name glpk now prints the expected "linearize_proximal_terms cannot be used with the FWPH algorithm" warning before the (expected) glpk-cannot-do-QPs failure
• New unit tests pass locally (pytest mpisppy/tests/test_config.py)
• CI on this PR

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[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 71.28%. Comparing base (90c3bec) to head (9187dde).

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #710      +/-   ##
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+ Coverage   71.19%   71.28%   +0.09%     
==========================================
  Files         154      154              
  Lines       19432    19438       +6     
==========================================
+ Hits        13835    13857      +22     
+ Misses       5597     5581      -16     

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