feat: add market-data-unwrap example and fix generators for cross-package types

- Add complete market-data-unwrap example demonstrating the unwrap annotation
  for map values that should serialize as arrays in JSON
- Fix mock generator to properly handle map fields
- Fix unwrap generator to use qualified type names for imported messages
- Fix client generator to conditionally import "bytes" (only when needed)
- Fix unwrap detection to check imported messages directly

The example shows a real-world use case based on the Alpaca Market Data API,
demonstrating how map<string, BarList> serializes as {"SYMBOL": [...]} instead
of {"SYMBOL": {"bars": [...]}}.

Co-Authored-By: Claude Opus 4.5 <[email protected]>

Author: SebastienMelki

examples/market-data-unwrap/.gitignore

@@ -0,0 +1,22 @@
+# Generated code
+api/
+docs/
+
+# Go build artifacts
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+*.test
+*.out
+
+# IDE
+.idea/
+.vscode/
+*.swp
+*.swo
+
+# OS
+.DS_Store
+Thumbs.db

examples/market-data-unwrap/Makefile

@@ -0,0 +1,96 @@
+.PHONY: demo install generate run client clean test test-unwrap
+
+# Complete demo workflow - installs tools, generates code, runs server
+demo:
+	@rm -rf api docs
+	@echo "🚀 Running market data unwrap demo..."
+	@$(MAKE) generate
+	@echo ""
+	@echo "✅ Demo ready! Starting server..."
+	@echo ""
+	@$(MAKE) run
+
+# Install required tools
+install:
+	@echo "Installing sebuf plugins..."
+	@go install github.com/bufbuild/buf/cmd/buf@latest
+	@go install google.golang.org/protobuf/cmd/protoc-gen-go@latest
+	@GOPROXY=direct go install github.com/SebastienMelki/sebuf/cmd/protoc-gen-go-http@latest
+	@GOPROXY=direct go install github.com/SebastienMelki/sebuf/cmd/protoc-gen-go-client@latest
+	@GOPROXY=direct go install github.com/SebastienMelki/sebuf/cmd/protoc-gen-openapiv3@latest
+	@echo "✅ Tools installed"
+
+# Generate code from proto files
+generate:
+	@echo "Fetching dependencies..."
+	@buf dep update
+	@echo "Generating code..."
+	@buf generate
+	@echo "Updating Go modules..."
+	@go mod tidy
+	@echo "✅ Code generated and dependencies updated"
+
+# Run the server
+run: generate
+	@go run main.go
+
+# Run the client example (requires server running)
+client:
+	@go run client_example.go
+
+# Clean generated files
+clean:
+	@rm -rf api docs
+	@echo "✅ Cleaned generated files"
+
+# Test the API endpoints with valid unwrapped response
+test:
+	@echo "Testing API endpoints..."
+	@echo ""
+	@echo "1. Get option bars (demonstrates unwrap serialization):"
+	@curl -s -X GET "http://localhost:8080/v2/options/bars?symbols=TSLA260123C00335000&timeframe=1Day" \
+		-H "APCA-API-KEY-ID: test-key" \
+		-H "APCA-API-SECRET-KEY: test-secret" \
+		| python3 -m json.tool
+	@echo ""
+	@echo "2. Get latest option bars:"
+	@curl -s -X GET "http://localhost:8080/v2/options/bars/latest?symbols=TSLA260123C00335000" \
+		-H "APCA-API-KEY-ID: test-key" \
+		-H "APCA-API-SECRET-KEY: test-secret" \
+		| python3 -m json.tool
+
+# Test to show the unwrap behavior - compare JSON structure
+test-unwrap:
+	@echo "Demonstrating unwrap behavior..."
+	@echo ""
+	@echo "With unwrap annotation, the response looks like:"
+	@echo '{"bars": {"TSLA260123C00335000": [{"c": 143.08, ...}, {"c": 145.34, ...}]}}'
+	@echo ""
+	@echo "Without unwrap, it would look like:"
+	@echo '{"bars": {"TSLA260123C00335000": {"bars": [{"c": 143.08, ...}, {"c": 145.34, ...}]}}}'
+	@echo ""
+	@echo "Making actual request to see the unwrapped response:"
+	@curl -s -X GET "http://localhost:8080/v2/options/bars?symbols=TSLA260123C00335000&timeframe=1Day" \
+		-H "APCA-API-KEY-ID: test-key" \
+		-H "APCA-API-SECRET-KEY: test-secret" \
+		| python3 -m json.tool
+
+# Test validation errors
+test-validation:
+	@echo "Testing validation errors..."
+	@echo ""
+	@echo "1. Missing required symbol parameter (should return 400):"
+	@curl -s -X GET "http://localhost:8080/v2/options/bars?timeframe=1Day" \
+		-H "APCA-API-KEY-ID: test-key" \
+		-H "APCA-API-SECRET-KEY: test-secret" \
+		| python3 -m json.tool
+	@echo ""
+	@echo "2. Invalid sort value (should return 400):"
+	@curl -s -X GET "http://localhost:8080/v2/options/bars?symbols=TSLA&timeframe=1Day&sort=invalid" \
+		-H "APCA-API-KEY-ID: test-key" \
+		-H "APCA-API-SECRET-KEY: test-secret" \
+		| python3 -m json.tool
+	@echo ""
+	@echo "3. Missing required header (should return 400):"
+	@curl -s -X GET "http://localhost:8080/v2/options/bars?symbols=TSLA&timeframe=1Day" \
+		| python3 -m json.tool