Implement infinite Git HTTP server

This server generates a new commit every time someone pulls from it.
Features:
- Pure Go implementation of Git object format and protocols
- No dependency on git CLI commands
- Thread-safe commit generation
- Read-only Git HTTP smart protocol support
- Comprehensive test suite

Each pull creates a new commit with a unique file containing a timestamp
and counter, making the repository grow infinitely with each pull operation.

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

internal/object/blob.go

@@ -0,0 +1,21 @@
+package object
+
+// Blob represents a Git blob object (file content).
+type Blob struct {
+	Content []byte
+}
+
+// NewBlob creates a new blob object.
+func NewBlob(content []byte) *Blob {
+	return &Blob{Content: content}
+}
+
+// Type returns the object type.
+func (b *Blob) Type() Type {
+	return TypeBlob
+}
+
+// Serialize returns the blob content.
+func (b *Blob) Serialize() []byte {
+	return b.Content
+}