engine: headless pictures draw the analysis setup's symbols

view::scene draws the boundary conditions, loads and interactions as the
viewport does (muted over a results plot) and frames them; Shown.sampled and
the MCP picture info's sampled_symbols list definitions drawn with a sample.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01NmAttHhUZTokgPeEJia8sm

docs/mcp.md

@@ -104,7 +104,7 @@ software on the computer.
 | `show_results` | `step?`, `field?`, `bands?`, `deformed?`, `scale?`, `mode?`, `frame?`, `time?` | The `results.*` commands its arguments ask for (`deformed: false` draws the undeformed mesh; `scale` is a factor, 0 for the undeformed shape so a sequence from 0 swings the deformation out, or `"auto"`); the reply has the contour range (smallest and largest value and their nodes: `field: "displacement"` gives the largest displacement), modes or frames. |
 | `probe` | `step?`, `nodes?`, `elements?`, `points?`, `forces?`, `mode?`, `frame?` | `solve.probe`: stored results at nodes, elements (explicit) or points (fluid). |
 | `reactions` | `step?`, `sets?`, `about?` | `results.reactions`: reaction force and moment per node set and in total. |
-| `screenshot` | `view?`, `camera?`, `source?` (window, model), `width?`, `height?`, `path?` | A PNG image content block and what it shows. Headless: a CPU render framing the model, the geometry and the results display (deformed shape, contour bands). Bridged: the whole app window drawn offscreen (`ui.capture`, the default) or a model render with the app's camera (`ui.render`). `view` turns the camera to a standard view first; `camera` `{yaw, pitch, distance?}` to any orientation, in degrees (yaw 0 looks along +Y, −45 is the iso view's; pitch is the elevation, clamped to ±90) and model units (`ui.camera`; headless, the picture is framed unless `distance` is given). Give one of the two; the orientation is kept for the next picture, so a sequence of `camera` angles orbits smoothly. |
+| `screenshot` | `view?`, `camera?`, `source?` (window, model), `width?`, `height?`, `path?` | A PNG image content block and what it shows. Headless: a CPU render framing the model, the geometry, the analysis setup's symbols (boundary conditions, loads, reference points, couplings; `sampled_symbols` lists definitions drawn with a sample) and the results display (deformed shape, contour bands). Bridged: the whole app window drawn offscreen (`ui.capture`, the default) or a model render with the app's camera (`ui.render`). `view` turns the camera to a standard view first; `camera` `{yaw, pitch, distance?}` to any orientation, in degrees (yaw 0 looks along +Y, −45 is the iso view's; pitch is the elevation, clamped to ±90) and model units (`ui.camera`; headless, the picture is framed unless `distance` is given). Give one of the two; the orientation is kept for the next picture, so a sequence of `camera` angles orbits smoothly. |
 | `undo`, `redo` | — | `edit.undo`, `edit.redo`. |
 
 Resources: `fieldcraft://model` (`model.info`) and `fieldcraft://commands` (the command catalog).