GroundGuard v0.2.0

GroundGuard v0.2.0 turns the v0.1 fact gate into a more usable integration
surface for real agent stacks.

Highlights

Extraction transparency: reports now expose suspected_numbers,
uncovered_numbers, and extraction_coverage, so users can see which
numeric-looking spans were not covered by deterministic extractors.
Pluggable extractors: register_extractor(...) lets teams add custom claim
extraction without forking GroundGuard.
Policy actions: tagged contradictions can be repaired from
Fact.display_value, or sent back through one reask pass.
Eval adapters: promptfoo and DeepEval helpers convert CoverageReport into
assertion-friendly payloads.
Performance groundwork: Ledger key lookup is indexed, and matcher candidate
lookup is bucketed by normalized unit.

python -m pytest
68 passed