Reorganize Docker build infrastructure for better maintainability

- Restructure from ollama37/ to docker/ with clear separation
- Separate builder and runtime images into dedicated directories
- Group environment scripts in builder/scripts/ subdirectory
- Add comprehensive root-level README.md (257 lines)
- Add .dockerignore files for optimized build contexts
- Enhance shell scripts with shebangs and documentation headers
- Update docker-compose.yml to build locally instead of pulling
- Add environment variables for GPU and host configuration
- Remove duplicate Dockerfile and confusing nested structure

New structure:
  docker/
  ├── README.md (comprehensive documentation)
  ├── docker-compose.yml (local build support)
  ├── builder/ (build environment: CUDA 11.4 + GCC 10 + Go 1.24)
  │   ├── Dockerfile
  │   ├── README.md
  │   ├── .dockerignore
  │   └── scripts/ (organized environment setup)
  └── runtime/ (production image)
      ├── Dockerfile
      ├── README.md
      └── .dockerignore

This reorganization eliminates confusion, removes duplication, and
provides a professional, maintainable structure for Tesla K80 builds.

docker/runtime/.dockerignore

@@ -0,0 +1,28 @@
+# Exclude documentation
+*.md
+README.md
+
+# Exclude builder files
+../builder/
+
+# Exclude volume data
+../volume/
+
+# Exclude docker-compose
+../docker-compose.yml
+
+# Exclude git
+.git/
+.gitignore
+.gitattributes
+
+# Exclude editor files
+.vscode/
+.idea/
+*.swp
+*.swo
+*~
+
+# Exclude OS files
+.DS_Store
+Thumbs.db