feat(p1): complete P1 foundation stage

- monorepo: pnpm workspace + go.work + pyproject.toml + commitlint/husky
- infra: docker-compose (minimal + full profiles) + init-sql + prometheus
- arch-scan: multi-language scanner skeleton (TS/Go/Python/Proto)
- shared-proto: buf v2 + classes.proto (ClassService CRUD contract)
- api-gateway: Go/Gin + JWT HS256 auth + reverse proxy + request ID
- classes: NestJS golden template (error system + observability + middleware + CRUD + tests)
- teacher-portal: Next.js + paper-feel UI design system
- CI/CD: 4 workflows (go/ts/py/proto)
- docs: migration guide + project_rules + coding-standards + git-workflow + ui-design-system + 004 + 9 module READMEs + known-issues + spec/plan migration + roadmap

services/api-gateway/go.mod

@@ -0,0 +1,14 @@
+module github.com/edu-cloud/api-gateway
+
+go 1.22
+
+require (
+	github.com/gin-gonic/gin v1.10.0
+	github.com/golang-jwt/jwt/v5 v5.2.1
+	github.com/google/uuid v1.6.0
+	go.opentelemetry.io/contrib/instrumentation/github.com/gin-gonic/gin/otelgin v0.52.0
+	go.opentelemetry.io/otel v1.27.0
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.27.0
+	go.opentelemetry.io/otel/sdk v1.27.0
+	go.uber.org/zap v1.27.0
+)