deps: update vendor dependencies for S3-compatible storage

Updates AWS SDK and removes Blazer B2 dependency in favor of unified
S3-compatible approach. Includes configuration examples and documentation.

🤖 Generated with [Claude Code](https://claude.ai/code)

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

vendor/github.com/aws/aws-sdk-go/private/protocol/unmarshal.go

@@ -0,0 +1,27 @@
+package protocol
+
+import (
+	"io"
+	"io/ioutil"
+
+	"github.com/aws/aws-sdk-go/aws/request"
+)
+
+// UnmarshalDiscardBodyHandler is a named request handler to empty and close a response's body
+var UnmarshalDiscardBodyHandler = request.NamedHandler{Name: "awssdk.shared.UnmarshalDiscardBody", Fn: UnmarshalDiscardBody}
+
+// UnmarshalDiscardBody is a request handler to empty a response's body and closing it.
+func UnmarshalDiscardBody(r *request.Request) {
+	if r.HTTPResponse == nil || r.HTTPResponse.Body == nil {
+		return
+	}
+
+	io.Copy(ioutil.Discard, r.HTTPResponse.Body)
+	r.HTTPResponse.Body.Close()
+}
+
+// ResponseMetadata provides the SDK response metadata attributes.
+type ResponseMetadata struct {
+	StatusCode int
+	RequestID  string
+}