refactor: migrate API from GraphQL to REST (TypeSpec/OpenAPI)

Replace the entire GraphQL stack (gqlgen, urql, graphql-codegen) with a
TypeSpec → OpenAPI 3.x pipeline using oapi-codegen for Go server stubs
and openapi-fetch + openapi-typescript for the frontend client.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/backend/api/echo_context.go b/backend/api/echo_context.go
new file mode 100644
index 0000000..b775850
--- /dev/null
+++ b/backend/api/echo_context.go
@@ -0,0 +1,21 @@
+package api
+
+import (
+	"context"
+	"errors"
+
+	"github.com/labstack/echo/v4"
+)
+
+type echoContextKey struct{}
+
+var errNoEchoContext = errors.New("echo context not found")
+
+func getEchoContext(ctx context.Context) echo.Context {
+	echoCtx, _ := ctx.Value(echoContextKey{}).(echo.Context)
+	return echoCtx
+}
+
+func WithEchoContext(ctx context.Context, echoCtx echo.Context) context.Context {
+	return context.WithValue(ctx, echoContextKey{}, echoCtx)
+}