docs: update version references to v1.4.0

Author: github-actions[bot]

README.md

@@ -103,7 +103,7 @@ import mcp.protobuf.annotations_pb2  # noqa: F401
 
 ```toml
 [dependencies]
-mcp-protobuf = "1.3.3"   # or cargo add mcp-protobuf for latest
+mcp-protobuf = "1.4.0"   # or cargo add mcp-protobuf for latest
 ```
 
 ## Quick Start

mcp/protobuf/python/README.md

@@ -10,8 +10,8 @@ Use the version matching the [grpc-mcp-gateway release](https://github.com/macha
 # Latest
 pip install grpc-mcp-gateway-protos
 
-# Or pin to a specific release (e.g. v1.3.3)
-pip install grpc-mcp-gateway-protos==1.3.3
+# Or pin to a specific release (e.g. v1.4.0)
+pip install grpc-mcp-gateway-protos==1.4.0
 ```
 
 ## What's included

mcp/protobuf/rust/README.md

@@ -14,7 +14,7 @@ Or add to `Cargo.toml` (replace with the version from the latest release):
 
 ```toml
 [dependencies]
-mcp-protobuf = "1.3.3"   # check crates.io for latest
+mcp-protobuf = "1.4.0"   # check crates.io for latest
 ```
 
 ## What's included