Fix PR #3761 RC: tag PrettierOverrideOptions projection gate

src/v4/TASKS.md

@@ -1840,7 +1840,8 @@ facts.
 
 `rustfmt.dag` established the pattern the sibling files follow:
 option coproducts → full config type → defaults data node →
-`*_layer` function for hierarchical override composition.
+`*ConfigPatch` (per-field `FieldPatch<T>` from `v4.std.patch`) →
+`*_layer(base, patch)` applying `apply_field_patch` per field.
 (Sibling files black.dag, gofmt.dag, prettier.dag, clang_format.dag,
 google_java_format.dag, swift_format.dag, ktfmt.dag, lean4_format.dag
 are already landed on main — see PRs #3650, #3651, #3652.)
@@ -1849,12 +1850,15 @@ are already landed on main — see PRs #3650, #3651, #3652.)
 - Each formatter file is **pure config substrate** — no dependency on
   `std/node.dag` or any compiler module. This keeps the formatter layer
   independent of the compiler pipeline and usable as a standalone fact bundle.
-- **Hierarchical override**: `*_layer(base: Config, outer: Config) ->
-  Config` where outer wins unconditionally. Layering is
-  `fold(layers, init: *_defaults, f: *_layer)`. Field-granularity patch
-  types (per-field `Override/Inherit` coproduct) are 🟡 gated —
-  feature: `formatter-config-patch` — dissolve when consumers need
-  partial override without full-config specification.
+- **Hierarchical override (per-field patches):** `*_layer(base: Config,
+  patch: *ConfigPatch) -> Config` rebuilds the config by applying
+  `apply_field_patch` on each field. Patches compose with right-biased
+  `compose_field_patch` / `field_patch_monoid` from `v4.std.patch`
+  (`Override { value }` replaces; `Inherit` defers to base). Layering is
+  `fold(layers, init: *_defaults, f: *_layer)` with one patch per layer.
+  The prior full-config `*_layer(base, outer) { outer }` scaffold and
+  `feature:formatter-config-patch` gate are dissolved in the T-4.16 follow-on.
+- **ConfigPatch record projection (interim mirrors):** `feature:config-patch-record-projection` in `v4.std.patch` — formatter `*ConfigPatch` records and `*_layer` bodies are hand mirrors until record-field projection derives them from `*Config`; owner **T-4.16 follow-on** (same lane as formatter-config-patch dissolution); consumers carry `consumer:config-patch-record-projection` tags until projection lands.
 - **Real options, not abstract axes**: each file models the actual
   formatter's documented option space (e.g., `rustfmt.toml` flags, not
   a synthetic `IndentWidth` abstraction shared across languages). A

src/v4/extdeps/formatters/black.dag

@@ -1,13 +1,14 @@
 // src/v4/extdeps/formatters/black.dag
 // Scope: Black 26.5.1 pyproject [tool.black] configuration model.
-// Owns: BlackTargetVersion, BlackTargetVersionPolicy, BlackRequiredVersionPolicy, BlackUnstableFeature, BlackConfig, black_defaults, black_layer.
-// Consumes: v4.std.collection { List }.
+// Owns: BlackTargetVersion, BlackTargetVersionPolicy, BlackRequiredVersionPolicy, BlackUnstableFeature, BlackConfig, black_defaults, BlackConfigPatch, black_layer.
+// Consumes: v4.std.collection { List }, v4.std.patch { FieldPatch, apply_field_patch }.
 // Status: T-4.16 scaffold — Black 26.5.1 pyproject schema.
 // Anchor: https://github.com/psf/black/blob/26.5.1/src/black/resources/black.schema.json
 
 module v4.extdeps.formatters.black
 
 import v4.std.collection { List }
+import v4.std.patch { FieldPatch, apply_field_patch }
 
 
 // 🟢 coproduct dissolution — CP-3229-GREEN-TERMINAL.
@@ -92,7 +93,44 @@ data black_defaults: BlackConfig = BlackConfig {
 }
 
 
-// 🟡 gated — feature: formatter-config-patch — bind T-4.16 follow-on — dissolve-on-arrival: BlackConfigPatch type with per-field Override<T>/Inherit arms replaces full-config layering; forbidden: full-config replacement where partial field override is needed.
-fn black_layer(base: BlackConfig, outer: BlackConfig) -> BlackConfig {
-  outer
+// 🟡 gated — consumer:config-patch-record-projection — bind v4.std.patch feature:config-patch-record-projection — dissolve-on-arrival: BlackConfigPatch projected from BlackConfig field set.
+type BlackConfigPatch {
+  line_length: FieldPatch<Int>
+  target_version: FieldPatch<BlackTargetVersionPolicy>
+  required_version: FieldPatch<BlackRequiredVersionPolicy>
+  pyi: FieldPatch<Bool>
+  ipynb: FieldPatch<Bool>
+  python_cell_magics: FieldPatch<List<String>>
+  skip_source_first_line: FieldPatch<Bool>
+  skip_string_normalization: FieldPatch<Bool>
+  skip_magic_trailing_comma: FieldPatch<Bool>
+  preview: FieldPatch<Bool>
+  unstable: FieldPatch<Bool>
+  enable_unstable_feature: FieldPatch<List<BlackUnstableFeature>>
+  include: FieldPatch<String>
+  exclude: FieldPatch<String>
+  extend_exclude: FieldPatch<String>
+  force_exclude: FieldPatch<String>
+}
+
+
+fn black_layer(base: BlackConfig, patch: BlackConfigPatch) -> BlackConfig {
+  BlackConfig {
+    line_length: apply_field_patch(base: base.line_length, patch: patch.line_length),
+    target_version: apply_field_patch(base: base.target_version, patch: patch.target_version),
+    required_version: apply_field_patch(base: base.required_version, patch: patch.required_version),
+    pyi: apply_field_patch(base: base.pyi, patch: patch.pyi),
+    ipynb: apply_field_patch(base: base.ipynb, patch: patch.ipynb),
+    python_cell_magics: apply_field_patch(base: base.python_cell_magics, patch: patch.python_cell_magics),
+    skip_source_first_line: apply_field_patch(base: base.skip_source_first_line, patch: patch.skip_source_first_line),
+    skip_string_normalization: apply_field_patch(base: base.skip_string_normalization, patch: patch.skip_string_normalization),
+    skip_magic_trailing_comma: apply_field_patch(base: base.skip_magic_trailing_comma, patch: patch.skip_magic_trailing_comma),
+    preview: apply_field_patch(base: base.preview, patch: patch.preview),
+    unstable: apply_field_patch(base: base.unstable, patch: patch.unstable),
+    enable_unstable_feature: apply_field_patch(base: base.enable_unstable_feature, patch: patch.enable_unstable_feature),
+    include: apply_field_patch(base: base.include, patch: patch.include),
+    exclude: apply_field_patch(base: base.exclude, patch: patch.exclude),
+    extend_exclude: apply_field_patch(base: base.extend_exclude, patch: patch.extend_exclude),
+    force_exclude: apply_field_patch(base: base.force_exclude, patch: patch.force_exclude),
+  }
 }