Video uploads: the uploader goes in the VOD's meta (Media's user_id is a number) (#68)

ddiff --git a/server/media/client.js b/server/media/client.js
iindex 258401a..bbc436b 100644
---- a/server/media/client.js
++++ b/server/media/client.js
@@@ -94,10 +94,13 @@ function createMediaClient({ config, fetchImpl = globalThis.fetch, log = console
      return {
          enabled,
  
--        /** A VOD row for an upload (Media's user_id is the uploader's usr_… subject; MediaHub owns the meaning). */
++        /**
++         * A VOD row for an upload. Media's user_id is an app-local number (Live's users), so the uploader's usr_… subject
++         * goes in the VOD's meta instead; MediaHub's own row is what says whose it is.
++         */
          vodCreate: ({ title, visibility = 'public', ownerSubject }) => call('', {
              root: vods(), method: 'POST',
--            json: { title: String(title || 'Video').slice(0, 300), visibility: ['public', 'unlisted', 'private'].includes(visibility) ? visibility : 'private', user_id: subjectHeader(ownerSubject) },
++            json: { title: String(title || 'Video').slice(0, 300), visibility: ['public', 'unlisted', 'private'].includes(visibility) ? visibility : 'private', meta: { source: 'openvibe.video upload', owner_subject: subjectHeader(ownerSubject) } },
          }),
          /** One part of the file, appended to the VOD's file in the order sent (segment 1: one continuous file). */
          vodChunk(vodId, buffer, contentType) {
ddiff --git a/test/helpers/media.js b/test/helpers/media.js
iindex a61ca6c..21538df 100644
---- a/test/helpers/media.js
++++ b/test/helpers/media.js
@@@ -110,7 +110,8 @@ async function startMedia({ maxSingle = 256 * 1024 * 1024 } = {}) {
              if (parts.length === 4 && req.method === 'POST') {
                  const body = JSON.parse(raw.toString('utf8') || '{}');
                  const id = ++vodSeq;
--                vods.set(id, { id, title: body.title, visibility: body.visibility, user_id: body.user_id, bytes: Buffer.alloc(0), types: [], status: 'recording' });
++                if (body.user_id != null && !/^\d+$/.test(String(body.user_id))) return problem(res, 500, 'vod.create', 'invalid input syntax for type bigint');   // as Media's column refuses it
++                vods.set(id, { id, title: body.title, visibility: body.visibility, user_id: body.user_id, meta: body.meta, bytes: Buffer.alloc(0), types: [], status: 'recording' });
                  return json(res, 201, { id });
              }
              const v = vods.get(Number(parts[4]));
ddiff --git a/test/video-uploads.test.js b/test/video-uploads.test.js
iindex 313a522..04c7ff8 100644
---- a/test/video-uploads.test.js
++++ b/test/video-uploads.test.js
@@@ -83,7 +83,8 @@ function vreq(base, path, { method = 'GET', cookie, form, json, body, same = tru
          const vod = [...t.media.vods.values()][0];
          assert.ok(vod.bytes.equals(file), 'Media has the file, byte for byte');
          assert.deepStrictEqual(vod.types, ['video/mp4', 'video/mp4'], 'QuickTime is sent as MP4');
--        assert.strictEqual(vod.user_id, kim.subject);
++        assert.strictEqual(vod.user_id, undefined, 'Media\'s user_id is a number: no subject there');
++        assert.strictEqual(vod.meta.owner_subject, kim.subject, 'the uploader is in the VOD\'s meta');
          const done1 = await vreq(t.base, `/api/v1/videos/${id}/complete`, { method: 'POST', cookie: kimCookie });
          assert.strictEqual(done1.status, 202);
          assert.strictEqual(done1.json().video.url, `/u/${id}`);