feat(goctl/rpc): support external proto imports with cross-package ty… (#5472)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

tools/goctl/rpc/test/proto/06_wellknown/gen.sh

@@ -0,0 +1,58 @@
+#!/usr/bin/env bash
+# Scenario 06: well-known type imports
+# Usage: bash gen.sh
+set -e
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+GOCTL_ROOT="$(cd "$SCRIPT_DIR/../../../.." && pwd)"
+GOCTL="$GOCTL_ROOT/bin/goctl"
+OUT="$SCRIPT_DIR/output"
+
+# Find well-known types include path
+PROTOC_INCLUDE=""
+PROTOC_BIN="$(which protoc 2>/dev/null || true)"
+if [ -n "$PROTOC_BIN" ]; then
+  CANDIDATE="$(cd "$(dirname "$PROTOC_BIN")/.." && pwd)/include"
+  [ -f "$CANDIDATE/google/protobuf/timestamp.proto" ] && PROTOC_INCLUDE="$CANDIDATE"
+fi
+if [ -z "$PROTOC_INCLUDE" ]; then
+  for d in /opt/homebrew/include /usr/local/include; do
+    [ -f "$d/google/protobuf/timestamp.proto" ] && PROTOC_INCLUDE="$d" && break
+  done
+fi
+if [ -z "$PROTOC_INCLUDE" ]; then
+  echo "Error: cannot find google/protobuf/timestamp.proto. Install protobuf (brew install protobuf)."
+  exit 1
+fi
+echo "Well-known types: $PROTOC_INCLUDE"
+
+# Build goctl from source
+go build -o "$GOCTL" "$GOCTL_ROOT"
+
+# Clean and initialize output directory
+rm -rf "$OUT" && mkdir -p "$OUT/pb"
+(cd "$OUT" && go mod init example.com/demo/s06_wellknown > /dev/null 2>&1)
+
+# Generate code
+cd "$SCRIPT_DIR"
+"$GOCTL" rpc protoc events.proto \
+  --go_out="$OUT/pb" \
+  --go-grpc_out="$OUT/pb" \
+  --zrpc_out="$OUT/rpc" \
+  --go_opt=paths=source_relative \
+  --go-grpc_opt=paths=source_relative \
+  --proto_path=. \
+  --proto_path="$PROTOC_INCLUDE"
+
+# Verify build
+echo "Running go mod tidy..."
+cd "$OUT" && go mod tidy
+echo "Checking build..."
+if go build ./...; then
+  echo "✅ Build passed"
+else
+  echo "❌ Build failed"
+  exit 1
+fi
+
+echo "Done. Output: $OUT"