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>

.github/workflows/build.yml

@@ -38,6 +38,9 @@ jobs:
   build:
     name: Build Verification
     runs-on: self-hosted
+    environment: cicd-1
+    env:
+      OLLAMA_VERSION: ${{ vars.OLLAMA_VERSION || '0.0.0' }}
     outputs:
       result: ${{ steps.build-tests.outcome }}