Cut 16.5.0 and bump the package version in pyproject.toml, uv.lock, and
CITATION.cff.

Minor: harden the agent's config authoring toward detail-first configs —
goal ordering is now breadth/coverage/Biolink/QC/efficiency, INSTRUCTIONS
gains a regex cookbook, qualifier guidance and a most-specific-predicate
rule, build_and_audit returns predicate_advice/multivalued_suspects/head
fidelity signals, and the deterministic proposer adds explode_by and fixes
demoted predicates (#135). Rebuild column coercion as one registry-driven
engine: uniform alias dropping across all coercions so losing aliases no
longer duplicate into supporting_text, the five clean-phase ops fused into
a single coerce_columns op, and selection/planning/application shared by
coerced_target and coerce_columns (#134). Also fix underscore-glued
adjusted p-value headers being misclassified as raw p_value, and bound
effect_type value coercion by distinct values (~6-18x faster) (#134).

Changelog:
- Versioned the Unreleased section as 16.5.0 and added the missing #135
  Added entry for the agent's detail-first config hardening; the five
  #134 entries already carried their PR links.

Docs: docs/agent.md and docs/configuration/table.md were updated by the
shipped changes; no additional release documentation was needed here.

Testing:
- uv run pytest -q -> 1164 passed, 16 skipped (94% coverage)
- uv run ruff check . && uv run ruff format --check . && uv run pyright
  -> clean / 0 errors
- uv lock --check -> up to date
- uv run mkdocs build --strict -> clean