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/04_transitive/gen.sh

@@ -0,0 +1,39 @@
+#!/usr/bin/env bash
+# Scenario 04: transitive 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="$SCRIPT_DIR/output"
+
+# Build goctl from source
+go build -o "$GOCTL" "$GOCTL_ROOT"
+
+# Clean and initialize output directory
+rm -rf "$OUT" && mkdir -p "$OUT/pb"
+(cd "$OUT" && go mod init example.com/demo/s04_transitive > /dev/null 2>&1)
+
+# Generate code
+cd "$SCRIPT_DIR"
+"$GOCTL" rpc protoc main.proto \
+  --go_out="$OUT/pb" \
+  --go-grpc_out="$OUT/pb" \
+  --zrpc_out="$OUT/rpc" \
+  --go_opt=paths=source_relative \
+  --go-grpc_opt=paths=source_relative \
+  --proto_path=.
+
+# Verify build
+echo "Running go mod tidy..."
+cd "$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"