Update docs, changelog, examples, and add ADRs for v1.2

- Add v1.1.0 and v1.2.0 changelog entries
- Add exclude field to config reference and example config
- Add ADRs documenting all major design decisions
- Fix step numbering in reverse_sync()
- Fix action.yml to copy VERSION file
- Add dist/ and .env to .gitignore
- Use refs/tags/ format for Nix flake tag refs

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

examples/forward.yml

@@ -62,7 +62,7 @@ jobs:
               done | sort -u | paste -sd ',' -)
           echo "targets=${TARGETS}" >> "$GITHUB_OUTPUT"
 
-      - uses: https://your-gitea.example.com/org/josh-sync@v1
+      - uses: https://your-gitea.example.com/org/josh-sync@v1.2
         with:
           direction: forward
           target: ${{ github.event.inputs.target || steps.detect.outputs.targets }}