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/ini/sep_tokens.go

@@ -0,0 +1,41 @@
+package ini
+
+import (
+	"fmt"
+)
+
+var (
+	emptyRunes = []rune{}
+)
+
+func isSep(b []rune) bool {
+	if len(b) == 0 {
+		return false
+	}
+
+	switch b[0] {
+	case '[', ']':
+		return true
+	default:
+		return false
+	}
+}
+
+var (
+	openBrace  = []rune("[")
+	closeBrace = []rune("]")
+)
+
+func newSepToken(b []rune) (Token, int, error) {
+	tok := Token{}
+
+	switch b[0] {
+	case '[':
+		tok = newToken(TokenSep, openBrace, NoneType)
+	case ']':
+		tok = newToken(TokenSep, closeBrace, NoneType)
+	default:
+		return tok, 0, NewParseError(fmt.Sprintf("unexpected sep type, %v", b[0]))
+	}
+	return tok, 1, nil
+}