Fix version injection for docker builds

- Add OLLAMA_VERSION build arg to Dockerfiles
- Update Makefile to pass version via --build-arg
- Add .env.example as local development reference
- Update build.yml to use cicd-1 environment for vars.OLLAMA_VERSION

Fixes #8

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docker/.env.example

@@ -0,0 +1,11 @@
+# Ollama37 Build Configuration
+# Copy this file to .env and customize as needed
+#
+# Usage:
+#   cp .env.example .env
+#   # Edit .env with your values
+#   make build
+
+# Ollama version to embed in the binary
+# This version is displayed by 'ollama --version' and in logs
+OLLAMA_VERSION=2.0.1