feat: MCP-Leseserver, Bibliotheksgrenze, Haertung des Lesepfads, Publish-Remote-Gate scharf (2.4.0)

Files changed:
- .gitea/workflows/ci.yml
- CHANGES.md
- README.md
- VERSION
- instructions/mcp-read-server.md
- tools/CONTRACT.md
- tools/README.md
- tools/chemenu/api.py
- tools/chemenu/commands/doctor.py
- tools/chemenu/commands/lint.py
- tools/chemenu/commands/search.py
- tools/chemenu/commands/types_cmd.py
- tools/chemenu/config.py
- tools/chemenu/corpus_cache.py
- tools/chemenu/errors.py
- tools/chemenu/frontmatter_io.py
- tools/chemenu/lint_core.py
- tools/chemenu/mcp/__init__.py
- tools/chemenu/mcp/__main__.py
- tools/chemenu/mcp/server.py
- tools/chemenu/page.py
- tools/chemenu/search/filters.py
- tools/chemenu/search/registry.py
- tools/chemenu/search/ripgrep.py
- tools/chemenu/search/service.py
- tools/chemenu/tests/conftest.py
- tools/chemenu/tests/test_api.py
- tools/chemenu/tests/test_corpus_cache.py
- tools/chemenu/tests/test_doctor.py
- tools/chemenu/tests/test_frontmatter_io.py
- tools/chemenu/tests/test_instructions_cmd.py
- tools/chemenu/tests/test_mcp_server.py
- tools/chemenu/tests/test_new_page.py
- tools/chemenu/tests/test_search.py
- tools/chemenu/type_resolver.py
- tools/chemenu/types_core.py
- tools/requirements-mcp.txt

.gitea/workflows/ci.yml

@@ -101,6 +101,10 @@ jobs:
           # instance does not measure this suite. Installed beside pytest for
           # the same reason pytest itself is.
           tools/.venv/bin/pip install --quiet pytest pytest-cov
+          # The MCP server's dependency is optional for an instance but not for
+          # CI: its tests skip without it, and a skipped golden test is exactly
+          # how the server's output and the CLI's would drift apart unnoticed.
+          tools/.venv/bin/pip install --quiet -r tools/requirements-mcp.txt
 
       - name: Tests
         # Not run with WIKI_TRACE=0: two telemetry tests assert that a trace is