## well_qc_plot()


Build a compact per-well QC figure (histogram + scatter + cell-cycle bar).


Usage

``` python
well_qc_plot(
    df,
    *,
    title=None,
    dna_norm_col=None,
    fig_size=(12, 7),
    size_units="cm",
    save=False,
    path=None,
    file_format="png",
    dpi=300
)
```


Layout -- 2×2 `GridSpec` matching the legacy per-well QC plot:

- Top-left: DNA-content histogram (log₂ x-axis).
- Bottom-left: DNA vs EdU scatter coloured by cell-cycle phase, with KDE overlay and threshold lines.
- Right (spans both rows): stacked cell-cycle phase barplot.

The caller is expected to pass a DataFrame that contains a single well's cells already filtered down (or trust the resolver / the underlying primitives to filter via the `well` column). The figure does not sample cells -- the histogram and scatter use all rows passed in.


## Parameters


`df: pd.DataFrame`  
Single-cell DataFrame with cell-cycle columns (`cell_cycle`, `intensity_mean_EdU_nucleus_norm`, and the normalised DNA-content column).

`title: str | None = None`  
Figure-level suptitle. If `None`, no title is drawn.

`dna_norm_col: str | None = None`  
Normalised DNA-content column to plot on the x-axis. Auto-resolved via `find_dna_norm_column()` when `None`.

`fig_size: tuple[float, float] = (12, 7)`  
Figure size in `size_units` (default: cm).

`size_units: str = ``"cm"`  
`"cm"` (default) or `"inches"`.

`save: bool = ``False`  
Save the figure to `path`.

`path: Path | None = None`  
Directory to save the figure into when `save=True`.

`file_format: str = ``"png"`  
Save format.

`dpi: int = ``300`  
Save resolution.


## Returns


`Figure`  
The composed matplotlib Figure.