feat: dual upload system — direct file storage + PeerTube API integration

Adds a parallel PeerTube upload system behind a feature flag (disabled by default
until upload quota is granted). When disabled, the existing direct file upload
path works unchanged.

Files:
- src/PeerTubeService.php — credential storage (encrypted), OAuth2 token
  retrieval, multipart upload to /api/v1/videos/upload
- migrations/021_peertube_settings.sql — peertube_settings singleton table
  + peertube_upload_enabled site_setting (default 0)
- admin/actions/settings.php — peertube section handler
- admin/parametres.php / templates/admin/parametres.php — PeerTube UI section
- partage/fichiers-fragment.php — shows file inputs when enabled, TODO notice otherwise
- ThesisCreateController / ThesisEditController — handlePeerTubeUpload()
- tfe.php — PeerTube iframe embed detection
- AdminLogger — logPeerTubeUpdate()

app/src/Controllers/ThesisEditController.php

@@ -334,6 +334,10 @@ class ThesisEditController
             $this->handleThesisFiles($thesisId, $post, $files['files']);
         }
 
+        // ── PeerTube video / audio uploads ────────────────────────────────────
+        $this->handlePeerTubeUpload($thesisId, trim($post['titre'] ?? ''), $files, 'peertube_video');
+        $this->handlePeerTubeUpload($thesisId, trim($post['titre'] ?? ''), $files, 'peertube_audio');
+
         // ── Website URL — add or update ──────────────────────────────────────
         $this->handleWebsiteUrl($thesisId, $post);
     }
@@ -685,6 +689,51 @@ class ThesisEditController
         return $info;
     }
 
+    /**
+     * Upload a video or audio file to PeerTube when the feature is enabled.
+     *
+     * @param int    $thesisId   Thesis to attach the result to.
+     * @param string $title      Title to use on PeerTube.
+     * @param array  $files      $_FILES array.
+     * @param string $inputName  'peertube_video' or 'peertube_audio'.
+     */
+    private function handlePeerTubeUpload(int $thesisId, string $title, array $files, string $inputName): void
+    {
+        $upload = $files[$inputName] ?? null;
+        if (!$upload || !isset($upload['error']) || $upload['error'] !== UPLOAD_ERR_OK) {
+            return;
+        }
+
+        require_once APP_ROOT . '/src/PeerTubeService.php';
+        if (!PeerTubeService::isEnabled($this->db)) {
+            return;
+        }
+
+        try {
+            $watchUrl = PeerTubeService::upload(
+                $this->db,
+                $upload['tmp_name'],
+                $title,
+                ''
+            );
+
+            $fileType = str_contains($inputName, 'audio') ? 'audio' : 'video';
+            $this->db->insertThesisFile(
+                $thesisId,
+                $fileType,
+                $watchUrl,
+                basename($upload['name']),
+                $upload['size'],
+                $upload['type'] ?? 'application/octet-stream',
+                null,
+                null
+            );
+            error_log("ThesisEditController: PeerTube upload OK → $watchUrl");
+        } catch (\Throwable $e) {
+            error_log('ThesisEditController: PeerTube upload failed — ' . $e->getMessage());
+        }
+    }
+
     /**
      * Add or update a website URL thesis_file row.
      *