3b25e0317f
Add the first implementation of core/rewriter.Rewriter as a plugin-only component following the bypass/admission pattern (single-value, no RewriterObject). Includes: - plugin/rewriter/proto/: protobuf definition with Rewrite RPC returning transformed data in the reply - x/rewriter/plugin/: gRPC and HTTP plugin clients - x/registry/rewriter.go: hot-reload-safe RewriterRegistry with wrapper - x/config/config.go: RewriterConfig, Config.Rewriters, ServiceConfig.Rewriter - x/config/parsing/rewriter/parse.go: config parser (plugin backends only) - core/handler/option.go: Rewriter field + RewriterOption on handler.Options - x/config/loader/loader.go: rewriter registration during startup - x/config/parsing/service/parse.go: inject rewriter into handler options