feat: implement order workflow, metrics, and handler unit tests

- implement UpdateOrderStatus and GetOrdersReport service methods
- implement all order, user handlers (UpdateMe, GetMyTrips, CancelOrder, GetOrder, etc.)
- extract OrderServicer interface for testability
- add Prometheus metrics middleware (requests total, duration)
- fix GetAll storage flavor for PostgreSQL ($1 placeholders)
- add 17 unit tests for order handlers via httptest
- wire Grafana datasource and update Prometheus scrape config
- update README with full API reference, pricing, roles, monitoring

go.mod

@@ -27,9 +27,14 @@ require (
 
 require (
 	github.com/apapsch/go-jsonmerge/v2 v2.0.0 // indirect
+	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/dgryski/go-rendezvous v0.0.0-20200823014737-9f7001d12a5f // indirect
+	github.com/dprotaso/go-yit v0.0.0-20220510233725-9ba8df137936 // indirect
 	github.com/fsnotify/fsnotify v1.9.0 // indirect
+	github.com/getkin/kin-openapi v0.133.0 // indirect
+	github.com/go-openapi/jsonpointer v0.21.0 // indirect
+	github.com/go-openapi/swag v0.23.0 // indirect
 	github.com/go-viper/mapstructure/v2 v2.4.0 // indirect
 	github.com/gosimple/unidecode v1.0.1 // indirect
 	github.com/huandu/go-clone v1.7.3 // indirect
@@ -37,16 +42,40 @@ require (
 	github.com/jackc/pgpassfile v1.0.0 // indirect
 	github.com/jackc/pgservicefile v0.0.0-20240606120523-5a60cdf6a761 // indirect
 	github.com/jackc/puddle/v2 v2.2.2 // indirect
+	github.com/josharian/intern v1.0.0 // indirect
 	github.com/knadh/koanf/maps v0.1.2 // indirect
+	github.com/mailru/easyjson v0.7.7 // indirect
 	github.com/mfridman/interpolate v0.0.2 // indirect
 	github.com/mitchellh/copystructure v1.2.0 // indirect
 	github.com/mitchellh/reflectwalk v1.0.2 // indirect
+	github.com/mohae/deepcopy v0.0.0-20170929034955-c48cc78d4826 // indirect
+	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
+	github.com/oapi-codegen/oapi-codegen/v2 v2.6.0 // indirect
+	github.com/oasdiff/yaml v0.0.0-20250309154309-f31be36b4037 // indirect
+	github.com/oasdiff/yaml3 v0.0.0-20250309153720-d2182401db90 // indirect
 	github.com/pelletier/go-toml v1.9.5 // indirect
+	github.com/perimeterx/marshmallow v1.1.5 // indirect
+	github.com/prometheus/client_golang v1.23.2 // indirect
+	github.com/prometheus/client_model v0.6.2 // indirect
+	github.com/prometheus/common v0.66.1 // indirect
+	github.com/prometheus/procfs v0.19.2 // indirect
 	github.com/sethvargo/go-retry v0.3.0 // indirect
+	github.com/speakeasy-api/jsonpath v0.6.0 // indirect
+	github.com/speakeasy-api/openapi-overlay v0.10.2 // indirect
+	github.com/vmware-labs/yaml-jsonpath v0.3.2 // indirect
+	github.com/woodsbury/decimal128 v1.3.0 // indirect
 	go.opentelemetry.io/otel v1.40.0 // indirect
 	go.opentelemetry.io/otel/trace v1.40.0 // indirect
 	go.uber.org/atomic v1.11.0 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
+	go.yaml.in/yaml/v2 v2.4.2 // indirect
+	golang.org/x/mod v0.32.0 // indirect
 	golang.org/x/sys v0.41.0 // indirect
 	golang.org/x/text v0.34.0 // indirect
+	golang.org/x/tools v0.41.0 // indirect
+	google.golang.org/protobuf v1.36.11 // indirect
+	gopkg.in/yaml.v2 v2.4.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
 )
+
+tool github.com/oapi-codegen/oapi-codegen/v2/cmd/oapi-codegen