chore: sync versions, update uv, expand dockerignore

- plugin.json: bump version 0.2.0 → 0.4.0 to match pyproject.toml
- Dockerfile: update uv 0.5.4 → 0.6 (global CLAUDE.md requires 0.10+)
- .dockerignore: exclude tests/, docs/, scripts/, commands/, .full-review/,
  .claude-plugin/, *.md (keep README.md) — reduces image size

.dockerignore

@@ -21,3 +21,11 @@ venv/
 env/
 .vscode/
 cline_docs/
+tests/
+docs/
+scripts/
+commands/
+.full-review/
+.claude-plugin/
+*.md
+!README.md