Resolve dynamic border and outline colors against the view trait collection in Fabric - #57837

…dii (#58028)

Summary:
Fixes #57841.

`outlineStyle: 'dotted'` and `'dashed'` render as solid on iOS. Android renders all three correctly, and the documented API lists all three values with no platform caveat.

### Root cause

`-[RCTViewComponentView invalidateLayer]` draws the outline through one of two paths:

- **Core Animation** — sets `_outlineLayer.borderWidth` / `.borderColor`. Cheap, but `CALayer` can only stroke a *solid* border.
- **Core Graphics** — `RCTAddContourEffectToLayer`, which forwards `outlineStyle` to `RCTGetBorderImage` and does honour dotted/dashed.

The branch choosing between them only looked at the border radii:

```objc
if (areBorderRadiiCircular(borderMetrics.borderRadii) && borderMetrics.borderRadii.topLeft.horizontal == 0) {
```

Every view **without a border radius** therefore took the Core Animation path, and its `outlineStyle` was silently dropped. Rounded views fell through to Core Graphics — which is why a dotted or dashed outline starts working as soon as a `borderRadius` is set.

The equivalent branch for *borders*, ~80 lines above, already gets this right: `useCoreAnimationBorderRendering` includes `borderMetrics.borderStyles.left == BorderStyle::Solid`, so a non-solid border falls through to Core Graphics. The outline branch never got the matching check when `outline` was implemented in #46444.

### Fix

Add the missing `outlineStyle == OutlineStyle::Solid` term, so non-solid outlines fall through to Core Graphics exactly as non-solid borders already do. Solid outlines keep the cheaper Core Animation path, so there is no cost for the common case.

### Why it went unnoticed

The only RNTester examples using `outlineStyle: 'dotted'` / `'dashed'` also set a `borderRadius`, so they only ever exercised the working path. This PR adds the square-cornered cases next to them, labelled, so all six combinations of `{square, rounded} × {solid, dashed, dotted}` are visible at once.

### Note on #57837

#57837 (open) rewrites the two `UIColor *outlineColor = ...` lines in this same block to resolve
dynamic colors against the trait collection. This change deliberately leaves those two lines
untouched — it only adds a term to the surrounding `if` — so the two patches touch disjoint lines
and should merge without conflict in either order.

## Changelog:

[IOS] [FIXED] - Render `outlineStyle: 'dotted'` and `'dashed'` on views without border radii

Pull Request resolved: #58028

Test Plan:
### Manual verification

RNTester → Components → View → Outline, iPhone 17 Pro Simulator (iOS 26.1), New Architecture, built from source (`RCT_USE_PREBUILT_RNCORE=0`).

| Before | After |
| --- | --- |
| <img src="https://raw.githubusercontent.com/neutronm/react-native/960889bd70d6cb18839f9d3586690908b0d8207d/assets/57841/before.png" width="420"> | <img src="https://raw.githubusercontent.com/neutronm/react-native/960889bd70d6cb18839f9d3586690908b0d8207d/assets/57841/after.png" width="420"> |
| `square dashed` and `square dotted` render solid | all six render correctly |

The rounded cases and every pre-existing example in the Outline screen are pixel-identical before and after; only the two square non-solid outlines change.

### Automated

| Command | Result |
| --- | --- |
| `yarn jest` | 222/223 suites, 5713 tests pass |
| `yarn flow-check` | `Found 0 errors` |
| `yarn lint` (`eslint --max-warnings 0 .`) | clean |
| `node ./scripts/clang-format.js <changed .mm files>` | no changes |
| `yarn build-types --validate` | `PASS  API snapshot is up to date.` |
| `tsc -p packages/react-native/__typetests__/tsconfig.json` | clean |
| `yarn test-ios` (`RNTesterUnitTests`) | `** TEST SUCCEEDED **` — 167 tests, 16 skipped, 0 failures |

The one Jest suite that did not pass in the full run (`GenerateComponentDescriptorH-test.js`) was a worker `SIGSEGV`, not an assertion failure; it passes 18/18 when run on its own.

### Unit tests

`React/Tests/Mounting/RCTViewComponentViewTests.mm` gains two cases next to the existing ones:

- `testSquareSolidOutlineUsesCoreAnimationBorder` — a square solid outline still uses `CALayer.borderWidth` (the fast path is not regressed).
- `testSquareDottedAndDashedOutlinesAreDrawnWithCoreGraphics` — square dotted and dashed outlines are drawn into `layer.contents` with `borderWidth == 0`.

`React/Tests/**` is excluded from the `React-Core` podspec, so these are not built by the OSS `RNTesterUnitTests` target. They were verified to compile against the installed pod headers with `clang -fsyntax-only -x objective-c++ -std=c++20`.

Reviewed By: cipolleschi

Differential Revision: D116779403

Pulled By: javache

fbshipit-source-id: b8d1f3508418016252ec9b1f9aaab7107c8f3b9f