refactor(config): type grid-style colors, fold validation (#118)

ConfigFiles/MBE/ui/grid_style.yaml

@@ -1,8 +1,6 @@
 # Grid Style Configuration
 # Color formats supported:
-#   - #RGB        (e.g., #FFF)
 #   - #RRGGBB     (e.g., #FFFFFF)
-#   - #ARGB       (e.g., #0FFF for transparent white)
 #   - #AARRGGBB   (e.g., #00FFFFFF for fully transparent white)
 # Alpha: 00 = fully transparent, FF = fully opaque
 

ConfigFiles/MOCVD/ui/grid_style.yaml

@@ -1,8 +1,6 @@
 # Grid Style Configuration
 # Color formats supported:
-#   - #RGB        (e.g., #FFF)
 #   - #RRGGBB     (e.g., #FFFFFF)
-#   - #ARGB       (e.g., #0FFF for transparent white)
 #   - #AARRGGBB   (e.g., #00FFFFFF for fully transparent white)
 # Alpha: 00 = fully transparent, FF = fully opaque
 

Docs/architecture/error-reporting.md

@@ -169,7 +169,7 @@ type. Its two `Result`-join sites (`LoadAsync`, `Save`) route each error through
 rather than joining raw `.Message` strings, so both the validation failures and the file-I/O failures render
 in the current culture. Eight typed producers back it (all in `SemiStep.Core/Configuration/`):
 
-- **Validation** (`GridStyleValidator`): `GridStyleConfigMissingError`, `GridStyleSectionMissingError`,
+- **Validation** (`GridStyleMapper`): `GridStyleConfigMissingError`, `GridStyleSectionMissingError`,
   `GridStyleOrientationInvalidError`, `GridStyleKeyMissingError`, `GridStyleHexColorInvalidError`. The
   orientation error carries its two expected values as properties (`ExpectedRows`/`ExpectedColumns`) rather
   than referencing the `internal GridOrientationValues` constants, which `ReasonLocalizer` (in `SemiStep.UI`)
@@ -184,7 +184,7 @@ the dropped `ex.Message` is logged at each consumer, and the `ExceptionalError`
 
 - **Editor consumer** — `GridStyleEditorViewModel.LoadAsync`/`Save` log each nested `ExceptionalError` at
   `LogWarning` after setting the localized `ErrorMessage`.
-- **Startup consumer** — `GridStyleLoader`/`GridStyleValidator` are also on the startup config-load path
+- **Startup consumer** — `GridStyleLoader`/`GridStyleMapper` are also on the startup config-load path
   (`ConfigFacade.LoadAndValidateAsync`, consumed by `Program.cs`), which logs the same nested
   `ExceptionalError` so a YAML parse detail is not lost at launch.
 

Docs/architecture/grid-style-configuration.md

@@ -41,37 +41,42 @@ are the deliberate exception: `GridStyleLoader.LoadAsync` reads exactly one file
 unambiguous: one config-dir maps to one style file. If styles were ever split across `ui/*.yaml`,
 write-back would have no single target, so single-file is intentional.
 
-The file header documents the accepted hex formats (`#RGB`, `#RRGGBB`, `#ARGB`, `#AARRGGBB`); the
+The file header documents the accepted hex formats (`#RRGGBB`, `#AARRGGBB`); the
 writer preserves that header on save.
 
 ## The load pipeline
 
 ```
 grid_style.yaml
   → GridStyleOptionsDto            (internal DTOs, snake_case [YamlMember], one per section)
-  → GridStyleValidator.Validate    (hex-format check; see "Known gap" below)
-  → GridStyleMapper.Map            (DTO → record, applies defaults)
+  → GridStyleMapper.Map            (DTO → record, aggregated per-key validation, applies defaults)
   → GridStyleOptions               (immutable record, SemiStep.Core, Avalonia-free)
   → AppConfiguration.GridStyle     (bundled by ConfigFacade)
   → DI singleton                   (UiDi.AddUi: AppConfiguration.GridStyle registered as GridStyleOptions)
 ```
 
-`ConfigFacade` loads the DTO, runs `GridStyleValidator`, calls `GridStyleMapper.Map`, and bundles the
-resulting `GridStyleOptions` record into `AppConfiguration`. `UiDi.AddUi` registers
+`ConfigFacade` loads the DTO, calls `GridStyleMapper.Map`, which validates and maps in one pass, and
+bundles the resulting `GridStyleOptions` record into `AppConfiguration`. `UiDi.AddUi` registers
 `AppConfiguration.GridStyle` as a `GridStyleOptions` singleton, so every consumer (the installers, the
 column factories, `ColumnWidthCalculator`) injects the same typed record.
 
 `GridStyleOptions` is an immutable record with a `Default` fallback used only by tests; the `#000000`
 cell-palette placeholders in `Default` are never rendered in production.
 
+**Interim (slice 4).** Colors are now the typed `StyleColor` value (channels `A`/`R`/`G`/`B`) end to
+end in the record; hex is a string only at the two I/O edges. Validation lives inside the load mapper —
+`GridStyleMapper.Map` returns a `Result<GridStyleOptions>` and accumulates every per-key error in one
+pass. The standalone `GridStyleValidator` and the editor's `HexColor` helper are gone. The full doc
+rewrite (and removal of the now-obsolete "Known gap" section) lands in slice 5.
+
 ## Record shape: nested per group (interim, slice 3)
 
 `GridStyleOptions` is no longer a flat 78-field record. It is a one-level nested root that composes ~10
 per-group records (`Fonts`, `Layout`, `Selection`, `ChangedCells`, `ReadOnlyCells`, `DisabledCells`,
 `Execution`, `StatusBar`, `ValidationPanel`, `Chrome`) plus the root-level `Orientation`. `ReadOnlyCells`
 and `DisabledCells` share one `DepthPalette` type. Consumers read short nested paths — `gridStyle.Fonts.CellFontSize`,
-`gridStyle.ReadOnlyCells.Depth1`, `gridStyle.Chrome.GridLine` — instead of the old flat fields. Colors stay
-`string` in this shape; typing them as `StyleColor` is slice 4.
+`gridStyle.ReadOnlyCells.Depth1`, `gridStyle.Chrome.GridLine` — instead of the old flat fields. Colors were
+`string` at slice 3; slice 4 typed them as `StyleColor` (see the interim note above).
 
 **The YAML file, the DTOs, and `GridStyleValidator` are unchanged** by this slice: the file on disk is
 byte-identical, the DTO layer keeps its nested snake_case shape and per-key error reporting, and the load
@@ -83,8 +88,8 @@ show a flat path (for example `GridStyleOptions.FontFamily`) now live under thei
 **Note for slice 4.** The error-path key `colors.grid_line` and the record path `Chrome.GridLine`
 deliberately diverge: `grid_line` is a loose field in the `colors:` DTO section (beside `grid_border` /
 `grid_background`), but the one-level record folds it into `Chrome` so the root carries no lone `string`.
-Slice 4 moves `GridStyleValidator`'s per-key checks into the load mapper; that mapper-resident validation
-**must keep emitting the `colors.grid_line` key**, not rename it to `chrome.grid_line`. The key names the
+Slice 4 moved those per-key checks into the load mapper (`GridStyleMapper.Map`); that mapper-resident
+validation keeps emitting the `colors.grid_line` key, not `chrome.grid_line`. The key names the
 YAML path the operator edits, not the record path.
 
 ## Resources projection
@@ -128,8 +133,8 @@ orientation: rows_as_steps   # canonical (rows = steps); or columns_as_steps (tr
 ```
 
 - **Values.** `rows_as_steps` (canonical) or `columns_as_steps` (transposed). An absent key
-  defaults to `rows_as_steps`, so existing files load unchanged. `GridStyleValidator` rejects
-  any other string with a config error naming both accepted values.
+  defaults to `rows_as_steps`, so existing files load unchanged. The load mapper
+  (`GridStyleMapper.Map`) rejects any other string with a config error naming both accepted values.
 - **Typed model.** The record carries a Core enum, `GridStyleOptions.Orientation`
   (`GridOrientation.RowsAsSteps | ColumnsAsSteps`), not the raw string. Parsing and
   serialization go through `GridOrientationValues` (`Configuration/Dto/`); an absent DTO value
@@ -237,9 +242,10 @@ GridStyleEditorWindow
 
 - **ViewModel.** Seeds a mutable draft from the loaded record (a separate copy, never the DI
   singleton). Colors are exposed as `Color` for the `ColorPicker`; sizes as `decimal?` for
-  `NumericUpDown`. Hex↔`Color` goes through an explicit `HexColor.ToHex` / `HexColor.Parse`, not
-  `Color.ToString()`. `CanSave` is gated by **both** the facade's color validation **and** VM-side
-  numeric range checks (font/padding/row-height/spacing/panel-height bounds). The editor surfaces
+  `NumericUpDown`. Channel↔`Color` conversion goes through `StyleColorConversions`
+  (`ToMediaColor` / `ToStyleColor`, in `SemiStep.UI/Styles`), not `Color.ToString()`. `CanSave` is gated
+  by VM-side numeric range checks alone (font/padding/row-height/spacing/panel-height bounds); an invalid
+  color is unrepresentable in the typed record, so the facade no longer color-validates on save. The editor surfaces
   effectively the whole record: all ~54 colors, 13 numerics, plus the font controls — one global
   font-family `ComboBox`, and a per-role weight `ComboBox` (curated 300–900 list) and italic
   `CheckBox`. The window groups these into two cards: **Fonts** (the family row plus a size / weight /
@@ -254,9 +260,11 @@ GridStyleEditorWindow
 - **Facade.** `GridStyleEditorFacade` is the only public Core seam for the editor:
   `Load(configDir)` → `Result<GridStyleOptions>`, `Validate(GridStyleOptions)` → `Result`,
   `Save(configDir, GridStyleOptions)` → `Task<Result>`. `Save` is async and runs the file write off the
-  UI thread (mirroring `Load`); the editor's `SaveCommand` awaits it. `Validate` stays synchronous —
-  `RecomputeCanSave` calls it per keystroke, and it is an in-memory pass with no I/O. The loader,
-  validator, writer, and the ~12 DTOs stay `internal`. The UI never touches Core internals directly.
+  UI thread (mirroring `Load`); the editor's `SaveCommand` awaits it. `Validate` is a vacuous
+  `Result.Ok()` pass-through — color validation now lives in the load mapper, so it validates nothing;
+  `RecomputeCanSave` still calls it per keystroke but `CanSave` turns on the numeric-range checks alone.
+  The method stays on the interface until slice 5 trims it. The loader, writer, and the ~12 DTOs stay
+  `internal`. The UI never touches Core internals directly.
   (Layering: the config stays in `SemiStep.Core`, settled by review; the editor reaches it only through
   this facade.)
 - **Writer.** `GridStyleWriter` maps the record back to the DTO (`GridStyleDtoMapper`), serializes with

SemiStep/SemiStep.Core/Configuration/ChangedCellColors.cs

@@ -1,5 +1,5 @@
 namespace SemiStep.Core.Configuration;
 
 public sealed record ChangedCellColors(
-	string Changed,
-	string ChangedSelected);
+	StyleColor Changed,
+	StyleColor ChangedSelected);

SemiStep/SemiStep.Core/Configuration/ChromeColors.cs

@@ -1,17 +1,17 @@
 namespace SemiStep.Core.Configuration;
 
 public sealed record ChromeColors(
-	string Info,
-	string Connected,
-	string Disconnected,
-	string LocalMode,
-	string Connecting,
-	string PanelBackground,
-	string PanelHeaderBackground,
-	string SubtleBorder,
-	string Separator,
-	string SecondaryForeground,
-	string GridBorder,
-	string GridBackground,
-	string HeaderForeground,
-	string GridLine);
+	StyleColor Info,
+	StyleColor Connected,
+	StyleColor Disconnected,
+	StyleColor LocalMode,
+	StyleColor Connecting,
+	StyleColor PanelBackground,
+	StyleColor PanelHeaderBackground,
+	StyleColor SubtleBorder,
+	StyleColor Separator,
+	StyleColor SecondaryForeground,
+	StyleColor GridBorder,
+	StyleColor GridBackground,
+	StyleColor HeaderForeground,
+	StyleColor GridLine);

SemiStep/SemiStep.Core/Configuration/DepthPalette.cs

@@ -1,13 +1,13 @@
 namespace SemiStep.Core.Configuration;
 
 public sealed record DepthPalette(
-	string Depth0,
-	string Depth1,
-	string Depth2,
-	string Depth3,
-	string Depth0Past,
-	string Depth1Past,
-	string Depth2Past,
-	string Depth3Past,
-	string Selected,
-	string Foreground);
+	StyleColor Depth0,
+	StyleColor Depth1,
+	StyleColor Depth2,
+	StyleColor Depth3,
+	StyleColor Depth0Past,
+	StyleColor Depth1Past,
+	StyleColor Depth2Past,
+	StyleColor Depth3Past,
+	StyleColor Selected,
+	StyleColor Foreground);

SemiStep/SemiStep.Core/Configuration/Dto/GridOrientationValues.cs

@@ -5,7 +5,7 @@ internal static class GridOrientationValues
 	public const string RowsAsSteps = "rows_as_steps";
 	public const string ColumnsAsSteps = "columns_as_steps";
 
-	// GridStyleValidator rejects unknown values before this parser runs; throwing here is
+	// GridStyleMapper rejects unknown values before this parser runs; throwing here is
 	// defense-in-depth against a future path that maps an unvalidated DTO.
 	public static GridOrientation Parse(string? value)
 	{

SemiStep/SemiStep.Core/Configuration/ExecutionPalette.cs

@@ -1,12 +1,12 @@
 namespace SemiStep.Core.Configuration;
 
 public sealed record ExecutionPalette(
-	string Depth0,
-	string Depth1,
-	string Depth2,
-	string Depth3,
-	string Depth0Past,
-	string Depth1Past,
-	string Depth2Past,
-	string Depth3Past,
-	string CurrentStepMarker);
+	StyleColor Depth0,
+	StyleColor Depth1,
+	StyleColor Depth2,
+	StyleColor Depth3,
+	StyleColor Depth0Past,
+	StyleColor Depth1Past,
+	StyleColor Depth2Past,
+	StyleColor Depth3Past,
+	StyleColor CurrentStepMarker);

SemiStep/SemiStep.Core/Configuration/Facade/ConfigFacade.cs

@@ -25,7 +25,7 @@ public static async Task<Result<AppConfiguration>> LoadAndValidateAsync(string c
 
 		var (properties, columns, groups, actions, gridStyle, connection, appUi) = loadResult.Value;
 
-		var gridStyleResult = GridStyleValidator.Validate(gridStyle);
+		var gridStyleResult = GridStyleMapper.Map(gridStyle);
 		if (gridStyleResult.IsFailed)
 		{
 			return Propagate(gridStyleResult, loadResult);
@@ -43,7 +43,7 @@ public static async Task<Result<AppConfiguration>> LoadAndValidateAsync(string c
 			return Propagate(defaultsResult, loadResult, xrefResult);
 		}
 
-		var mapResult = MapToDomain(properties, columns, groups, actions, gridStyle, connection, appUi);
+		var mapResult = MapToDomain(properties, columns, groups, actions, gridStyleResult.Value, connection, appUi);
 
 		if (mapResult.IsFailed)
 		{
@@ -118,7 +118,7 @@ private static Result<AppConfiguration> MapToDomain(
 		List<Dto.ColumnDto> columns,
 		Dictionary<string, Dictionary<int, string>> groups,
 		List<Dto.ActionDto> actions,
-		Dto.GridStyleOptionsDto? gridStyle,
+		GridStyleOptions gridStyle,
 		Dto.ConnectionDto? connection,
 		Dto.AppUiOptionsDto? appUi)
 	{
@@ -152,15 +152,13 @@ private static Result<AppConfiguration> MapToDomain(
 			mappedActions.Add(action.Id, action);
 		}
 
-		var mappedGridStyle = GridStyleMapper.Map(gridStyle);
-
 		var plcConfiguration = ConnectionMapper.Map(connection);
 
 		var appUiOptions = AppUiOptionsMapper.Map(appUi);
 
 		return Result.Ok(new AppConfiguration(
 			mappedProperties, mappedColumns, mappedGroups,
-			mappedActions, mappedGridStyle, plcConfiguration, appUiOptions));
+			mappedActions, gridStyle, plcConfiguration, appUiOptions));
 	}
 
 	private sealed record LoadedSections(

SemiStep/SemiStep.Core/Configuration/GridStyleEditorFacade.cs

@@ -2,15 +2,15 @@
 
 using SemiStep.Core.Configuration.Loaders;
 using SemiStep.Core.Configuration.Mapping;
-using SemiStep.Core.Configuration.Validation;
 
 namespace SemiStep.Core.Configuration;
 
 /// <summary>
-/// The single public Core seam for the in-app style editor. <see cref="Validate"/> and
-/// <see cref="Save"/> check color hex format only; numeric-range validation (font sizes, paddings,
-/// row height, spacing, panel height) is the caller's responsibility — the editor view model enforces
-/// those bounds before invoking <see cref="Save"/>.
+/// The single public Core seam for the in-app style editor. Color hex validation now lives in
+/// <see cref="GridStyleMapper"/>, which parses and validates in one pass on <see cref="Load"/>; an invalid
+/// color is unrepresentable in <see cref="GridStyleOptions"/>, so <see cref="Save"/> writes without a
+/// pre-write gate. Numeric-range validation (font sizes, paddings, row height, spacing, panel height) is the
+/// caller's responsibility — the editor view model enforces those bounds before invoking <see cref="Save"/>.
 /// </summary>
 public sealed class GridStyleEditorFacade : IGridStyleEditorFacade
 {
@@ -24,28 +24,18 @@ public async Task<Result<GridStyleOptions>> Load(string configDir)
 			return loadResult.ToResult<GridStyleOptions>();
 		}
 
-		var validation = GridStyleValidator.Validate(loadResult.Value);
-		if (validation.IsFailed)
-		{
-			return validation.ToResult<GridStyleOptions>();
-		}
-
-		return Result.Ok(GridStyleMapper.Map(loadResult.Value));
+		return GridStyleMapper.Map(loadResult.Value);
 	}
 
 	public Result Validate(GridStyleOptions options)
 	{
-		return GridStyleValidator.Validate(GridStyleDtoMapper.Map(options));
+		// Deliberate vacuous pass-through: a typed GridStyleOptions cannot hold an invalid color, so there is
+		// nothing to validate here. The method stays on IGridStyleEditorFacade until slice 5 trims the interface.
+		return Result.Ok();
 	}
 
 	public async Task<Result> Save(string configDir, GridStyleOptions options)
 	{
-		var validation = Validate(options);
-		if (validation.IsFailed)
-		{
-			return validation;
-		}
-
 		return await _gridStyleWriter.SaveAsync(configDir, options);
 	}
 }