chore: uncomment CODEOWNERS entries with crate-specific paths

.github/CODEOWNERS

@@ -5,11 +5,33 @@
 # Default owners for everything in the repo
 * @maintainers
 
-# Crate-specific (uncomment and add handles when you have designated owners)
-# /crates/quicproquo-core/     @owner1
-# /crates/quicproquo-proto/    @owner1
-# /crates/quicproquo-server/   @owner1
-# /crates/quicproquo-client/   @owner1
-# /crates/quicproquo-p2p/      @owner1
-# /schemas/                        @owner1
-# /docs/                           @owner1
+# Security-critical: crypto primitives, MLS, hybrid KEM
+/crates/quicproquo-core/             @maintainers
+
+# Wire format: protobuf definitions, Cap'n Proto schemas
+/crates/quicproquo-proto/            @maintainers
+/proto/                              @maintainers
+
+# Auth and server-side domain logic
+/crates/quicproquo-server/           @maintainers
+
+# Client SDK: auth, conversation store, messaging pipeline
+/crates/quicproquo-sdk/              @maintainers
+
+# CLI/TUI client
+/crates/quicproquo-client/           @maintainers
+
+# RPC framework: framing, middleware, QUIC transport
+/crates/quicproquo-rpc/              @maintainers
+
+# Key transparency
+/crates/quicproquo-kt/               @maintainers
+
+# Plugin ABI (no_std C-ABI boundary)
+/crates/quicproquo-plugin-api/       @maintainers
+
+# P2P transport
+/crates/quicproquo-p2p/              @maintainers
+
+# CI and infrastructure
+/.github/                            @maintainers