Prepare OpenHCS for image.sc announcement

[trissim]

Outcome

Prepare the project-facing surfaces for an image.sc beta announcement without freezing or cutting a release.

What changed

• replace the stale 0.6 announcement with a release-neutral, compile-first image.sc draft and readiness checklist
• make local MCP adoption concrete in the README and landing page with bounded inspect/compile and one-well execution prompts
• restore changelog coverage through v0.7.11
• add contribution, conduct, security, citation, issue, and pull-request guidance
• add exact regressions for stale pipeline paths (Trying to add new pipeline after moving old one fails #70), default rerun overwrite (FileExistsError on re-run — memory backend refuses to overwrite existing results #72), and saved function-pattern synchronization (Saving code in function pattern editor does not update steps #73)
• advance PyQT-reactive to the declaration-owner fix merged on its canonical main for the remaining PyQt6 Qt.DisplayRole crash path (Error on windows install of openhcs #61)
• remove the superseded BBBC021/BBBC038 microscope handlers and dropdown choices; declared source bindings now own those dataset imports while benchmark IDs remain provenance
• make runtime-equivalence registration independent of incidental import order
• rename Napari component placement from slice to layer, so Napari now exposes layer/stack while Fiji retains its genuine Z-slice mode
• make desktop installer source tests build a metadata-discovered wheelhouse for OpenHCS and its checked-out first-party dependencies, while preserving the separate PyPI mode

The terminology change is owned by the shared viewer protocol rather than mirrored locally:

• ZMQRuntime #2 is merged and declares distinct LAYER and SLICE modes
• PolyStore #5 consumes LAYER for Napari routing and remains draft until a ZMQRuntime package containing that declaration is published
• OpenHCS consumes the same declaration and keeps all genuine array/Fiji slice terminology unchanged

Verification

QT_QPA_PLATFORM=offscreen .venv/bin/python -m pytest tests/unit/test_build_website.py tests/unit/test_path_cache.py tests/unit/test_file_materialization_options.py tests/unit/pyqt_gui/test_dual_editor_session.py -q
28 passed

QT_QPA_PLATFORM=offscreen .venv/bin/python -m pytest tests/unit/test_microscope_handler_identity.py tests/unit/test_source_binding_workspace.py -q
37 passed

QT_QPA_PLATFORM=offscreen .venv/bin/python -m pytest tests/integration/test_cellprofiler_generated_pipeline.py::test_bbbc021_cppipe_executes_named_channel_bindings_through_zmq tests/integration/test_cellprofiler_generated_pipeline.py::test_bbbc021_canonical_illum_cppipe_materializes_declared_images_through_zmq -q
2 passed

.venv/bin/python -m pytest tests/unit/test_dataset_registry.py tests/unit/test_runner_cellprofiler_compatibility.py tests/integration/test_benchmark_openhcs_adapter_cppipe.py -q
15 passed

QT_QPA_PLATFORM=offscreen .venv/bin/python -m pytest tests/unit/test_streaming_service.py tests/unit/test_napari_streaming_handlers.py::test_napari_layer_title_authority_uses_stream_display_name_policy tests/unit/test_napari_streaming_handlers.py::test_napari_component_display_coordinator_splits_declared_image_layouts -q
18 passed

# ZMQRuntime
PYTHONPATH=src ../../.venv/bin/python -m pytest tests/test_viewer_protocol.py -q
4 passed

# PolyStore against the source ZMQRuntime declaration
PYTHONPATH=src:../zmqruntime/src ../../.venv/bin/python -m pytest tests/test_streaming_receiver_core.py -q
13 passed

PYTHONPATH=src:../ObjectState/src:../python-introspect/src QT_QPA_PLATFORM=offscreen ../../.venv/bin/python -m pytest tests/test_log_viewer_lifecycle.py -q
5 passed

XDG_CACHE_HOME=/tmp/openhcs-test-cache .venv/bin/python -m openhcs.mcp.dev_client --timeout-seconds 30 health
status: ok, errors: []

The current checkout imports openhcs.gui_startup and pyqt_reactive.process_launch successfully, with source and installed distribution versions both reporting 0.7.11.

In integration run 30712718093, both Windows and macOS desktop-installer-source-test jobs pass with candidate dependency wheels. The Windows job completes the two-pass install/update and real viewer smoke that previously failed against released ZMQRuntime 0.1.21.

Release boundary

No dependency package or OpenHCS release is created by this PR. The future publication order is:

1. publish ZMQRuntime with ViewerComponentMode.LAYER
2. publish PolyStore with Napari layer routing
3. update OpenHCS production dependency floors and cut the later OpenHCS release

The PyQT-reactive source-clone fix is also merged, but its production dependency floor should be updated only after the corresponding PyQT-reactive package is published. This PR stays draft until those dependency artifacts exist and the package-level CI path can be green.