Remove legacy viz scripts and viz_legacy module; fix lint for viz extras

- Delete analyze.py, export.py (nD_perfect_reactor) and viz.py (1D
  shocktube examples) which all used mfc.viz_legacy
- Delete toolchain/mfc/viz_legacy.py (superseded by ./mfc.sh viz)
- Update nD_perfect_reactor/README.md to remove analyze.py invocation
- lint.sh: install mfc[viz] optional extras before running pylint and
  test_viz so optional imports (imageio, h5py, textual) resolve cleanly
- tui.py: suppress R0903 on MFCPlot (inherits many methods from parent)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: sbryngelson

examples/1D_inert_shocktube/viz.py

@@ -3,12 +3,4 @@
 Reference:
 > G. B. Skinner and G. H. Ringrose, “Ignition Delays of a Hydrogen—Oxygen—Argon Mixture at Relatively Low Temperatures”, J. Chem. Phys., vol. 42, no. 6, pp. 2190–2192, Mar. 1965. Accessed: Oct. 13, 2024.
 
-```bash
-$ python3 analyze.py
-Induction Times ([OH] >= 1e-6):
- + Skinner et al.: 5.200e-05 s
- + Cantera:        5.130e-05 s
- + (Che)MFC:       5.130e-05 s
-```
-
 <img src="result.png" height="MAX_HEIGHT"/>

examples/1D_reactive_shocktube/viz.py

@@ -12,6 +12,9 @@ for arg in "$@"; do
     esac
 done
 
+log "(venv) Installing$MAGENTA viz$COLOR_RESET optional dependencies for linting..."
+uv pip install -q "$(pwd)/toolchain[viz]" 2>/dev/null || pip install -q "$(pwd)/toolchain[viz]"
+
 log "(venv) Running$MAGENTA pylint$COLOR_RESET on$MAGENTA MFC$COLOR_RESET's $MAGENTA""toolchain$COLOR_RESET."
 
 pylint -d R1722,W0718,C0301,C0116,C0115,C0114,C0410,W0622,W0640,C0103,W1309,C0411,W1514,R0401,W0511,C0321,C3001,R0801,R0911,R0912 "$(pwd)/toolchain/"

examples/nD_perfect_reactor/README.md

@@ -56,7 +56,7 @@
 # Plot widget
 # ---------------------------------------------------------------------------
 
-class MFCPlot(PlotextPlot):  # pylint: disable=too-many-instance-attributes
+class MFCPlot(PlotextPlot):  # pylint: disable=too-many-instance-attributes,too-few-public-methods
     """Plotext plot widget.  Caller sets ._x_cc / ._y_cc / ._data / ._ndim /
     ._varname / ._step before calling .refresh()."""