fix: remove destructive migrate rewrite, add replay source attribution and warning drain

src/cli/commands/migrate/rewriters/route-rewriter.ts

@@ -2,7 +2,7 @@
  * Route rewriter for APOPHIS migrate command.
  *
  * Responsibilities:
- * - Rewrite route schema annotations (e.g., x-validate-runtime → runtime)
+ * - Rewrite route schema annotations
  * - Preserve schema structure and formatting
  * - Handle annotations in Fastify route definitions
  * - Detect ambiguous annotations and require manual choice
@@ -40,10 +40,12 @@ export interface AmbiguousRoutePattern {
 
 /**
  * Mapping of deprecated route schema annotations to their modern equivalents.
+ * x-validate-runtime is intentionally NOT here — it is the current, active annotation
+ * used by contract.ts and hook-validator.ts for per-route runtime validation opt-out.
+ * Rewriting it to 'runtime' would break it, since 'runtime' is a top-level plugin
+ * config option, not a valid route schema annotation.
  */
-export const LEGACY_ROUTE_ANNOTATIONS: Record<string, string> = {
-  'x-validate-runtime': 'runtime',
-};
+export const LEGACY_ROUTE_ANNOTATIONS: Record<string, string> = {};
 
 /**
  * Ambiguous route patterns that require manual choice.