Ship decision_template.docx into the Docker image

The analysis DOCX exporter loads skills/docx/decision_template.docx at
runtime, but .dockerignore was excluding the entire skills/ tree and
Dockerfile didn't COPY it — so the deployed container returned
'Template not found at /app/skills/docx/decision_template.docx' on
every /export-docx request.

  .dockerignore  Re-include the one file we need at runtime.
  Dockerfile    COPY that single file into /app/skills/docx/.

Documentation and SKILL.md stay outside the image.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.dockerignore

@@ -9,6 +9,8 @@ web/static/
 web/__pycache__/
 scripts/
 skills/
+!skills/docx/
+!skills/docx/decision_template.docx
 docs/
 legacy/
 node_modules/