Implement pure Go Git HTTP server without CLI dependencies

Major rewrite to eliminate git CLI dependency:
- Created object package for Git object format handling (blob, tree, commit)
- Implemented packfile generation from scratch
- Rewrote repo initialization to create Git repos without CLI
- Implemented git-upload-pack protocol in pure Go
- Updated all server handlers to use new implementation
- Added Git packet tracing to test.sh for debugging
- Fixed tests to work with new implementation

The server now works entirely with Go code, no git commands needed.
Clone operations work correctly, but pull operations still have protocol
negotiation issues that need further debugging.

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

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

test.sh

@@ -1,5 +1,8 @@
 #!/bin/bash
-set -e
+set -ex
+
+# Enable Git packet tracing for debugging
+export GIT_TRACE_PACKET=1
 
 # Cleanup function
 cleanup() {
@@ -12,8 +15,11 @@ cleanup() {
 # Trap EXIT to ensure cleanup happens
 trap cleanup EXIT
 
+# Kill any existing server in case it was not cleaned up
+lsof -ti:9876 | xargs kill -9 2>/dev/null || true
+
 echo "Starting infinite-git server..."
-go run . -addr :9876 -repo /tmp/test-infinite-git &
+PORT=9876 REPO_PATH=/tmp/test-infinite-git go run . &
 SERVER_PID=$!
 
 # Give server time to start
@@ -43,10 +49,6 @@ echo "Files after second pull:"
 ls -la
 
 echo "Checking commits..."
-git log --oneline
+git --no-pager log --oneline
 
-# Test directory cleanup
-cd /
-rm -rf "$TEST_DIR"
-
-echo "Test complete!"
+echo "Test complete!"