AI: a MediaRef is a Media object id (fetched at /o/<id>); legacy refs are refused (C-24) (#54)

ddiff --git a/server/fetcher.js b/server/fetcher.js
iindex fc140c4..da7ab55 100644
---- a/server/fetcher.js
++++ b/server/fetcher.js
@@@ -14,8 +14,10 @@
   *     public hop (an allow-listed host that redirects must not reach the loopback Media service)
   *   - a byte cap, a timeout and cancellation on every transfer
   * data: URLs (images a caller sends inline) are decoded locally with a size cap — never fetched.
-- * A MediaRef resolves to the public Media URL for the legacy kinds; med_ ids are an explicit
-- * `media.unresolvable` until the Wave 4 object API exists.
++ * A MediaRef (a Media object id, med_…) resolves to that object's public bytes URL, <Media>/o/<id>:
++ * Media serves a public, ready object there (redirecting to its storage copy) and answers 404 for a
++ * private one, so a MediaRef never reaches more than its URL would. The `legacy:<svc>:<kind>:<id>`
++ * form is refused since 2026-10-11 (compatibility register C-24: no run ever sent one).
   */
  const dns = require('dns');
  const net = require('net');
@@@ -26,6 +28,9 @@ const os = require('os');
  const path = require('path');
  const { AiError } = require('./util');
  
++/** A Media object id (contracts media/media-ref.v1: med_ + a ULID). */
++const MEDIA_OBJECT_ID = /^med_[0-9A-HJKMNP-TV-Z]{26}$/;
++
  const blocked = new net.BlockList();
  for (const [a, p] of [['0.0.0.0', 8], ['10.0.0.0', 8], ['100.64.0.0', 10], ['127.0.0.0', 8], ['169.254.0.0', 16], ['172.16.0.0', 12], ['192.0.0.0', 24],
      ['192.0.2.0', 24], ['192.88.99.0', 24], ['192.168.0.0', 16], ['198.18.0.0', 15], ['198.51.100.0', 24], ['203.0.113.0', 24], ['224.0.0.0', 4], ['240.0.0.0', 4]]) blocked.addSubnet(a, p, 'ipv4');
@@@ -217,22 +222,11 @@ function createFetcher(config, { transport = null } = {}) {
          return url;
      }
  
--    /** A MediaRef -> the public URL of that object (legacy kinds only for now). */
++    /** A MediaRef -> the public bytes URL of that Media object. */
      function mediaRefUrl(ref) {
--        const id = ref && ref.media_id;
--        const mm = /^legacy:([a-z][a-z0-9-]{1,39}):(vod|clip|file|paste|thumbnail|avatar):([A-Za-z0-9._/-]{1,200})$/.exec(String(id || ''));
--        if (!mm) throw new AiError(422, 'media.unresolvable', `media ${id} cannot be resolved by this service yet`);
--        const [, , kind, key] = mm;
--        const base = m.publicUrl;
--        if (key.includes('..')) throw new AiError(422, 'media.unresolvable', 'bad media key');
--        switch (kind) {
--            case 'vod': return `${base}/v/${encodeURIComponent(key)}`;
--            case 'clip': return `${base}/c/${encodeURIComponent(key)}`;
--            case 'thumbnail': return `${base}/t/${encodeURIComponent(key)}`;
--            case 'paste': return `${base}/p/${encodeURIComponent(key)}/raw`;
--            case 'file': return `${base}/f/${key.split('/').map(encodeURIComponent).join('/')}`;
--            default: throw new AiError(422, 'media.unresolvable', `media kind ${kind} is not fetched`);
--        }
++        const id = String((ref && ref.media_id) || '');
++        if (!MEDIA_OBJECT_ID.test(id)) throw new AiError(422, 'media.unresolvable', `media ${id || '(none)'} is not a Media object id (med_…)`);
++        return `${m.publicUrl}/o/${id}`;
      }
  
      /** Image input { url } | { data_url } | { media: MediaRef } -> { mediaType, base64 }. */
ddiff --git a/server/workflows/common-schemas.js b/server/workflows/common-schemas.js
iindex b3e7ff2..b2cc1f0 100644
---- a/server/workflows/common-schemas.js
++++ b/server/workflows/common-schemas.js
@@@ -4,7 +4,7 @@
  const MEDIA_REF = {
      type: 'object', additionalProperties: false, required: ['media_id'],
      properties: {
--        media_id: { type: 'string', pattern: '^(med_[0-9A-HJKMNP-TV-Z]{26}|legacy:[a-z][a-z0-9-]{1,39}:(vod|clip|file|paste|thumbnail|avatar):[A-Za-z0-9._/-]{1,200})$' },
++        media_id: { type: 'string', pattern: '^med_[0-9A-HJKMNP-TV-Z]{26}$' },
          role: { type: 'string' }, variant: { type: 'string' },
      },
  };
ddiff --git a/test/ssrf.test.js b/test/ssrf.test.js
iindex f1ccb01..496a3f6 100644
---- a/test/ssrf.test.js
++++ b/test/ssrf.test.js
@@@ -53,8 +53,13 @@ t.test('URL rules: https + allow-listed host only', async () => {
      }
      assert.ok(f.judge('https://openvibe.media/v/1'));
      assert.ok(f.judge('https://ai.openvibe.network/x'), '*.openvibe.network');
--    assert.strictEqual(f.mediaRefUrl({ media_id: 'legacy:live:vod:42' }), 'https://openvibe.media/v/42');
--    assert.throws(() => f.mediaRefUrl({ media_id: 'med_01JAB2C3D4E5F6G7H8J9K0MNPA' }), e => e.code === 'media.unresolvable');
++    // A MediaRef is a Media object id and resolves to its public bytes URL (Media 404s a private one).
++    assert.strictEqual(f.mediaRefUrl({ media_id: 'med_01JAB2C3D4E5F6G7H8J9K0MNPA' }), 'https://openvibe.media/o/med_01JAB2C3D4E5F6G7H8J9K0MNPA');
++    assert.ok(f.judge(f.mediaRefUrl({ media_id: 'med_01JAB2C3D4E5F6G7H8J9K0MNPA' })), 'the resolved URL passes the same URL rules');
++    // The legacy:<svc>:<kind>:<id> form is refused (C-24), as is anything else that is not an object id.
++    for (const id of ['legacy:live:vod:42', 'med_01JAB2C3D4E5F6G7H8J9K0MNP', 'med_01JAB2C3D4E5F6G7H8J9K0MNPA/../x', '', null]) {
++        assert.throws(() => f.mediaRefUrl({ media_id: id }), e => e.code === 'media.unresolvable', String(id));
++    }
  });
  
  t.test('an allow-listed NAME that resolves to an internal address is refused at connect time', async () => {