fix: harden engine, enrich failure diagnostics, close adoption gaps

- P0: CLI verify now honors  test budget with seeded multi-sample
- P0: Observe sampling enforced via Math.random() gate in hook-validator
- P1: Remove misleading undici-mock-agent isolation option
- P1: Qualify reuses shared discoverRouteDetails() with warnings
- P1: Chaos/scenario config exposed via preset schema
- P1: README/docs limitations updated to current state
- P2: Nested response annotations prefer 2xx deterministically
- P2: --changed documented as heuristic in verify.md

- Add observe sink tests (sampling 0/1, sink failure non-interference)
- Add verify runs regression tests (scale, determinism, variants)
- Add configured-scenario qualify test (independent of OAuth fixture)
- Add coverageBreakdown to qualify artifacts (per-gate route coverage)
- Add production-style observe example with real sink in docs/observe.md
- Add nightly/staging vs PR gating guidance to docs/qualify.md

- Enrich VerifyFailure with formula-aware diagnostics:
  status:201 => 'HTTP 200', body field checks => actual values
- Remove stale observe CLI activation message
- Document outbound mocks as process-global in getting-started.md
- Refresh APOPHIS_ADOPTION_AUDIT.md with current state

903 tests pass, build clean, typecheck clean.

src/extensions/jwt.ts

@@ -7,7 +7,7 @@
  *
  * Example:
  * ```typescript
- * import { jwtExtension } from 'apophis-fastify/extensions/jwt'
+ * import { jwtExtension } from '@apophis/fastify/extensions/jwt'
  *
  * await fastify.register(apophis, {
  *   extensions: [
@@ -286,6 +286,7 @@ function resolveFormat(ctx: PredicateContext, config: JwtExtensionConfig): unkno
 export function jwtExtension(config: JwtExtensionConfig = {}): ApophisExtension {
   return {
     name: 'jwt',
+    productionSafe: true,
 
     headers: ['jwt_claims', 'jwt_header', 'jwt_valid', 'jwt_format'],