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.

docs/quality.md

@@ -44,7 +44,7 @@ import {
   applyChaosToExecution,
   createChaosEventArbitrary,
   formatChaosEvents,
-} from 'apophis-fastify'
+} from '@apophis/fastify'
 
 // Apply pre-generated chaos events to a context
 const result = applyChaosToExecution(ctx, events)
@@ -71,7 +71,7 @@ Automatically rerun failing tests with varied seeds to detect non-deterministic
 ### Usage
 
 ```javascript
-import { FlakeDetector } from 'apophis-fastify'
+import { FlakeDetector } from '@apophis/fastify'
 
 const detector = new FlakeDetector({
   sameSeedReruns: 1,    // Rerun with same seed
@@ -121,7 +121,7 @@ Measure contract strength by injecting synthetic bugs. A "mutation" is a small c
 ### Usage
 
 ```javascript
-import { runMutationTesting } from 'apophis-fastify/quality/mutation'
+import { runMutationTesting } from '@apophis/fastify/quality/mutation'
 
 const report = await runMutationTesting(fastify, {
   runs: 10,
@@ -176,7 +176,7 @@ console.log('Weak contracts:', report.weakContracts)
 Test a specific mutation without running the full suite:
 
 ```javascript
-import { testMutation } from 'apophis-fastify/quality/mutation'
+import { testMutation } from '@apophis/fastify/quality/mutation'
 
 const killed = await testMutation(fastify, contract, mutation, {
   runs: 10,