feat(core): implement Git repository operations with gRPC services

- Add advertise_refs functionality for Git protocol communication
- Implement archive service with TAR/ZIP format support and streaming
- Create blame service for Git file annotation with line tracking
- Add branch management including create, delete, rename and compare operations
- Implement merge checking with conflict detection and fast-forward handling
- Add cherry-pick functionality for applying commits between branches
- Integrate gix library for Git repository operations and object handling
- Add comprehensive test suite covering all Git operations
- Implement proper error handling and repository validation
- Add pagination support for large result sets
- Create protobuf definitions for all Git operations and data structures
- Add build system for gRPC code generation and dependency management

LICENSE

@@ -0,0 +1,58 @@
+PolyForm Noncommercial License 1.0.0
+
+Copyright (c) 2024 gitks contributors
+
+License: "Noncommercial" as defined below.
+
+"Noncommercial" means primarily intended for or directed towards the
+advantage or monetary gain of a business, commercial entity, or for-profit
+organization. A use is "Noncommercial" if it is not primarily intended for
+or directed towards commercial advantage or monetary compensation.
+
+1. Grant of Copyright License. Subject to the terms of this license,
+   Licensor grants you a worldwide, royalty-free, non-exclusive, limited
+   license to exercise the Licensed Rights in the Licensed Material for
+   Noncommercial purposes only.
+
+2. Grant of Patent License. Subject to the terms of this license, Licensor
+   grants you a worldwide, royalty-free, non-exclusive, limited license
+   under patent claims owned or controlled by Licensor that are embodied
+   in the Licensed Material as furnished by Licensor, to make, use, sell,
+   offer for sale, have made, and import the Licensed Material for
+   Noncommercial purposes only.
+
+3. Limitations. The license granted in Section 1 and Section 2 above is
+   expressly limited to Noncommercial purposes. You may not exercise the
+   Licensed Rights for the purpose of providing services to third parties,
+   including but not limited to:
+   (a) offering the Licensed Material as a hosted or managed service
+       where third parties access or use the Licensed Material;
+   (b) offering the Licensed Material as part of a product or service
+       that is sold, licensed, or otherwise provided for monetary gain;
+   (c) using the Licensed Material to provide consulting, support, or
+       other services for monetary gain.
+
+4. Acceptance. Any use of the Licensed Material in violation of this
+   license will automatically terminate your rights under this license
+   for the current and all future versions of the Licensed Material.
+
+5. Patents. If you institute patent litigation against any entity
+   (including a cross-claim or counterclaim in a lawsuit) alleging that
+   the Licensed Material constitutes direct or contributory patent
+   infringement, then any patent licenses granted to you under this
+   license for the Licensed Material shall terminate as of the date
+   such litigation is filed.
+
+6. Disclaimer of Warranty. THE LICENSED MATERIAL IS PROVIDED "AS IS" AND
+   WITHOUT ANY WARRANTY OF ANY KIND. LICENSOR DISCLAIMS ALL WARRANTIES,
+   EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED WARRANTIES
+   OF TITLE, NON-INFRINGEMENT, MERCHANTABILITY, OR FITNESS FOR A
+   PARTICULAR PURPOSE.
+
+7. Limitation of Liability. IN NO EVENT WILL LICENSOR BE LIABLE TO YOU
+   FOR ANY DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL, OR
+   CONSEQUENTIAL DAMAGES ARISING OUT OF THESE TERMS OR IN CONNECTION
+   WITH THE USE OR INABILITY TO USE THE LICENSED MATERIAL, EVEN IF
+   LICENSOR HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
+
+For the full license text, see: https://polyformproject.org/licenses/noncommercial/1.0.0