v1.0.0 — Feature flags and A/B experiments that add up

Every A/B tool shows two numbers and a green arrow. The arrow is the easy part.

• Deterministic bucketing — SHA-256 of salt:flag:user into 10,000 buckets, the same answer on every server without a session
• Targeting rules that explain themselves: every evaluation returns the reason and the index of the rule that fired
• Statistics without libraries — Wilson intervals, a two-proportion z-test, a Beta-posterior probability of beating control, sample size and MDE
• Guardrail metrics: a background job writes a significant regression into the audit log by itself
• An idempotent daily rollup — a second run rewrites the day instead of adding to it; the screens read only the rollup
• 63 tests on PostgreSQL, light and dark themes, README in three languages