Update changelogs from fern repo (#5256)

Co-authored-by: dsinghvi <10870189+dsinghvi@users.noreply.github.com>

Author: fern-support

fern/products/sdks/generators/csharp/changelog/2026-04-30.mdx

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+## 2.63.3
+**`(fix):`** Fix dynamic snippets emitting wrong property name when PascalCase(property)
+collides with class name (e.g. CatalogV1Id.catalog_v1_id). The snippet
+generator now uses the same rename logic as the SDK (appending "_") so that
+generated examples compile without CS0542 / CS0117 errors.
+
+

fern/products/sdks/generators/java/changelog/2026-04-30.mdx

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+## 4.6.4
+**`(fix):`** Fix dynamic snippet generation for multipart/form-data endpoints with file parameters.
+Previously, when a file value was not provided in the example, the file argument was
+omitted from the snippet, causing subsequent arguments to shift and produce compile errors
+(e.g. `incompatible types: <Op>Request cannot be converted to Optional<java.io.File>`).
+Now emits `null` for missing file arguments to keep positional args aligned.
+
+

fern/products/sdks/generators/swift/changelog/2026-04-30.mdx

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+## 0.34.1
+**`(fix):`** Properly escape control characters, real newlines, real backslashes, and
+real double quotes when emitting Swift string literals that wrap raw user
+data (example values, dynamic snippet inputs, JSON wire test fixtures).
+Previously, an example value containing a real newline (e.g. a multi-line
+iCalendar string) caused the generated SDK to fail Swift compilation with
+`error: unterminated string literal`.
+
+