feat(web): add OpenAPI TypeScript codegen and CI freshness check

Генерируем api.gen.ts из docs/openapi.yaml (openapi-typescript), добавляем scripts/check-openapi-gen.sh в CI. Закрываем решение по X-Tenant-Id как unimplemented; обновляем docs/README под React/ReUI и apps/web.

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/web/src/types/api.ts

@@ -1,3 +1,13 @@
+/**
+ * Hand-written UI DTO aliases used by routes/queries.
+ * Machine SoT from OpenAPI: `./api.gen.ts` (regenerate: `pnpm --filter @evobgp/web run openapi:gen`).
+ * Prefer aligning new fields with schemas in docs/openapi.yaml + regenerating api.gen.ts.
+ */
+import type { components } from './api.gen'
+
+/** Re-export generated OpenAPI components for gradual adoption. */
+export type OpenAPISchemas = components['schemas']
+
 // ---- Pagination ----
 export type Page<T> = {
   items: T[]