Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@ktor-http/api/ktor-http.api`:
- Around line 1517-1547: The public constructors for
io.ktor.http.content.PartData and nested classes (PartData$BinaryChannelItem,
PartData$BinaryItem, PartData$FileItem, PartData$FormItem) were changed to add a
Function1 `release` parameter which breaks binary compatibility; restore
compatibility by adding overload constructors that match the old signatures and
delegate to the new constructors (e.g., provide constructors without the
`release` Function1 that supply a default no-op release), or if the change is
intentional make it explicit in the API by marking it as a breaking change and
add clear migration notes in the public docs and changelog referencing the
modified symbols PartData.<init>, PartData$BinaryChannelItem.<init>,
PartData$BinaryItem.<init>, PartData$FileItem.<init>, and
PartData$FormItem.<init>.

In `@ktor-http/ktor-http-cio/common/src/io/ktor/http/cio/CIOMultipartDataBase.kt`:
- Line 35: The non-blocking cleanup is not actually wired up: update eventToData
to call event.releaseSuspend() instead of the blocking event.release(), and in
partToData when creating FormItem and FileItem supply the suspend release
callback (release = { part.releaseSuspend() }) instead of using the old
disposable lambda (dispose); this ensures previousPart?.release() will invoke
the suspend release provided by those items and removes remaining blocking calls
in eventToData and partToData.

In `@ktor-http/ktor-http-cio/common/src/io/ktor/http/cio/Multipart.kt`:
- Around line 88-91: In releaseSuspend ensure the body channel is always
discarded even if headers.await() throws: wrap the headers.await().release()
call in a try block and call body.discard() in a finally block so body.discard()
runs regardless of exceptions; update the releaseSuspend implementation (the
suspend method named releaseSuspend) to use try/finally around headers.await()
and headers.await().release() while still calling body.discard() in the finally.

---

Nitpick comments:
In `@ktor-http/common/src/io/ktor/http/content/Multipart.kt`:
- Around line 17-26: Update the KDoc for the sealed class PartData to stop
documenting the deprecated dispose property and instead document the new suspend
release property: replace the `@property` dispose line with an `@property` release
entry that describes its purpose (a suspend function to be invoked when the part
is no longer needed) and note that dispose is deprecated and release should be
used; reference the PartData class and its release: suspend () -> Unit signature
so readers can find the correct member.

Verify each finding against the current code and only fix it if needed.

Nitpick comments:
In `@ktor-http/common/src/io/ktor/http/content/Multipart.kt`:
- Around line 23-28: Update the KDoc for the sealed class PartData to document
the new suspend release callback as the preferred cleanup lifecycle hook and
mark dispose as deprecated; specifically, revise the class-level and constructor
parameter docs to explain that release is the canonical asynchronous cleanup
method to be invoked by consumers (and may be called automatically by the
framework), that dispose remains for binary compatibility but is deprecated, and
include usage guidance and any concurrency/exception semantics for release;
reference the PartData class and its constructor parameters release and dispose
when updating the documentation.