[chore] media pipeline improvements (#3110)

* don't set emoji / media image paths on failed download, migrate FileType from string to integer

* fix incorrect uses of util.PtrOr, fix returned frontend media

* fix migration not setting arguments correctly in where clause

* fix not providing default with not null column

* whoops

* ensure a default gets set for media attachment file type

* remove the exclusive flag from writing files in disk storage

* rename PtrOr -> PtrOrZero, and rename PtrValueOr -> PtrOrValue to match

* slight wording changes

* use singular / plural word forms (no parentheses), is better for screen readers

* update testmodels with unknown media type to have unset file details, update attachment focus handling converting to frontend, update tests

* store first instance in ffmpeg wasm pool, fill remaining with closed instances

1 files changed, 12 insertions, 3 deletions

diff --git a/internal/util/ptr.go b/internal/util/ptr.go
index d7c30da85..8a89666c4 100644
--- a/internal/util/ptr.go
+++ b/internal/util/ptr.go
@@ -43,10 +43,19 @@ func PtrIf[T comparable](t T) *T {
 	return &t
 }
 
-// PtrValueOr returns either value of ptr, or default.
-func PtrValueOr[T any](t *T, _default T) T {
+// PtrOrZero returns either value of ptr, or zero.
+func PtrOrZero[T any](t *T) T {
+	if t == nil {
+		var z T
+		return z
+	}
+	return *t
+}
+
+// PtrOrValue returns either contained value of ptr, or 'value'.
+func PtrOrValue[T any](t *T, value T) T {
 	if t != nil {
 		return *t
 	}
-	return _default
+	return value
 }