docs: audit + fix — remove observe CLI refs, correct defaults, fix public API imports, add historical banners

docs/observe.md

@@ -29,21 +29,19 @@ Observe mode requires a reporting sink. Configure it in your environment policy:
 environments: {
   staging: {
     name: 'staging',
-    allowVerify: true,
-    allowObserve: true,
-    allowQualify: false,
-    allowChaos: false,
-    allowBlocking: false,
-    requireSink: true
+    allowedModes: ['verify', 'observe'],
+    blockQualify: true,
+    requireSink: true,
+    allowBlocking: false
   }
 }
 ```
 
-APOPHIS supports these sink types:
+You implement sinks for your observability backend. Common categories:
 
-- **Logs**: Structured logging of contract violations
-- **Metrics**: Counter and histogram metrics for violation rates
-- **Traces**: Distributed tracing integration for violation context
+- **Logs**: Structured logging of contract violations (pino, winston)
+- **Metrics**: Counter and histogram metrics for violation rates (Prometheus, OpenTelemetry)
+- **Traces**: Distributed tracing integration for violation context (OpenTelemetry, Jaeger)
 
 ## Sampling
 
@@ -97,10 +95,12 @@ profiles: {
 
 Validate your observe config before deployment with doctor:
 
-## Exit Codes
+## Validation (via Doctor)
+
+Validate observe configuration with `apophis doctor --mode observe`:
 
 | Code | Meaning |
-|---|---|
+|---|---|---|
 | 0 | Observe config is valid and safe |
 | 2 | Safety violation or invalid config |