feat: add redmine-cli containerized CLI tool

Merge the redmine-cli work from the EnableAI repo into KNEL-AIMiddleware as the
canonical home for AI middleware. This is a standalone CLI (python-redmine 2.5.0)
that lists, shows, creates, updates, and closes Redmine issues via docker run.
Complements the existing mcp-redmine MCP server (protocol-native) with a
direct-invocation tool for interactive use.

Verified end-to-end against projects.knownelement.com: whoami, projects,
statuses, list, show, create, update, and close all tested successfully.

Also records host-cleanliness conventions (docker/tea only on host; custom
images to Gitea registry) in AGENTS.md, and adds a CLI Tools section to
STATUS.md.

redmine-cli/Dockerfile

@@ -0,0 +1,16 @@
+FROM python:3.12-slim
+
+ENV PYTHONUNBUFFERED=1 \
+    PYTHONDONTWRITEBYTECODE=1 \
+    PIP_NO_CACHE_DIR=1
+
+WORKDIR /app
+
+COPY requirements.txt .
+RUN pip install -r requirements.txt
+
+COPY src/redmine_cli.py /usr/local/bin/redmine-cli
+RUN chmod +x /usr/local/bin/redmine-cli
+
+ENTRYPOINT ["redmine-cli"]
+CMD ["--help"]