Polish build flow and README formatting

- update-lockfile.yml: rename workflow to "Update lockfiles"
- release.yml: add explicit uv python install 3.13 for consistency with other workflows
- docker-publish.yml: rename cpu cache scope from linux/amd64-cpu to cpu (now multi-arch)
- README: add GitHub release version badge and License badge
- README: shorten QUALITY_REPLACEMENT table cell

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

.github/workflows/docker-publish.yml

@@ -192,8 +192,8 @@ jobs:
           file: ./Dockerfile
           platforms: linux/amd64,linux/arm64
           build-args: VARIANT=cpu
-          cache-from: type=gha,scope=linux/amd64-cpu
-          cache-to: type=gha,mode=max,scope=linux/amd64-cpu
+          cache-from: type=gha,scope=cpu
+          cache-to: type=gha,mode=max,scope=cpu
           github-token: ${{ secrets.GITHUB_TOKEN }}
           push: true
           tags: ${{ steps.cpu-tag.outputs.tag }}