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/internal/sdkio/byte.go

@@ -0,0 +1,12 @@
+package sdkio
+
+const (
+	// Byte is 8 bits
+	Byte int64 = 1
+	// KibiByte (KiB) is 1024 Bytes
+	KibiByte = Byte * 1024
+	// MebiByte (MiB) is 1024 KiB
+	MebiByte = KibiByte * 1024
+	// GibiByte (GiB) is 1024 MiB
+	GibiByte = MebiByte * 1024
+)

vendor/github.com/aws/aws-sdk-go/internal/sdkio/io_go1.6.go

@@ -0,0 +1,11 @@
+//go:build !go1.7
+// +build !go1.7
+
+package sdkio
+
+// Copy of Go 1.7 io package's Seeker constants.
+const (
+	SeekStart   = 0 // seek relative to the origin of the file
+	SeekCurrent = 1 // seek relative to the current offset
+	SeekEnd     = 2 // seek relative to the end
+)

vendor/github.com/aws/aws-sdk-go/internal/sdkio/io_go1.7.go

@@ -0,0 +1,13 @@
+//go:build go1.7
+// +build go1.7
+
+package sdkio
+
+import "io"
+
+// Alias for Go 1.7 io package Seeker constants
+const (
+	SeekStart   = io.SeekStart   // seek relative to the origin of the file
+	SeekCurrent = io.SeekCurrent // seek relative to the current offset
+	SeekEnd     = io.SeekEnd     // seek relative to the end
+)