fix(capture): add --growing-file flag to raw2bmx command

Without --growing-file, raw2bmx writes body partitions via --part but
does NOT mark them as closed partitions with self-contained index table
segments. Premiere Pro's growing-file reader requires closed partitions
to safely parse an in-progress MXF and detect that the duration has
advanced — without this flag the file imports fine but never shows
growth in the timeline.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

services/capture/src/capture-manager.js

@@ -673,6 +673,7 @@ class CaptureManager {
     // recorded duration grows mid-write.
     const bmx = [
       'raw2bmx', '-t', 'op1a', '-o', '"$OUT"', '-f', frameRate,
+      '--growing-file',
       '--part', String(GROWING_PART_INTERVAL_FRAMES),
       rawFlag, '"$VF"',
       '-s', '48000', '-q', '16', '--audio-chan', String(ach), '--pcm', '"$AF"',