feat(uploads): a video track is no longer a reason to reject (ADR-033)

Only no-audio, unreadable length and too-long are refused. ReasonVideo is gone.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

internal/uploads/validate.go

@@ -18,8 +18,8 @@ type Limits struct {
 }
 
 // Probe is what inspecting an uploaded file revealed. It is the input to Validate
-// because a name or MIME type cannot say whether a container carries video: a
+// because a name or MIME type cannot say what a container holds: a Teams recording
-// Teams voice-only export is typically an .mp4 with no video stream.
+// is an .mp4 whether or not the camera was on.
 type Probe struct {
 	Duration time.Duration
 	HasAudio bool
@@ -30,7 +30,6 @@ type Probe struct {
 type Reason string
 
 const (
-	ReasonVideo      Reason = "video"
 	ReasonNoAudio    Reason = "no_audio"
 	ReasonTooLong    Reason = "too_long"
 	ReasonTooLarge   Reason = "too_large"
@@ -46,13 +45,13 @@ type RejectError struct {
 
 func (e *RejectError) Error() string { return string(e.Reason) + ": " + e.Message }
 
-// Validate decides whether a probed file may be transcribed. Video is checked
+// Validate decides whether a probed file may be transcribed. A video track is NOT
-// first so a video file is always refused as video, whatever its length.
+// a reason to refuse: a Teams meeting with the camera off is still an .mp4 with a
+// video track, so rejecting video would reject the primary use case. Only the audio
+// is used (Probe.HasVideo is recorded so the user can be told the video was
+// ignored). What IS refused: no audio at all, an unreadable length, too long.
 func Validate(p Probe, l Limits) error {
 	switch {
-	case p.HasVideo:
-		return &RejectError{Reason: ReasonVideo, Message: "This file contains a video track. " +
-			"Only audio recordings are supported for now; video upload is tracked in issue #28."}
 	case !p.HasAudio:
 		return &RejectError{Reason: ReasonNoAudio, Message: "This file has no audio track to transcribe."}
 	case p.Duration <= 0: