feat: add admin API endpoints for video management, update frontend to use new API routes

Co-authored-by: Copilot <copilot@github.com>

frontend/app/main.py

@@ -523,6 +523,39 @@ def admin_videos():
     return render_template("admin/videos.html")
 
 
+# ── Admin API proxies (same-origin for browser JS, avoids mixed-content) ──
+
+@app.get("/api/admin/videos")
+@admin_required
+def api_admin_list_videos():
+    resp = _api("GET", "/admin/videos", token=session["access_token"])
+    return jsonify(resp.json()), resp.status_code
+
+
+@app.post("/api/admin/videos/<job_id>/retry")
+@admin_required
+def api_admin_retry_video(job_id: str):
+    resp = _api(
+        "POST", f"/admin/videos/{job_id}/retry", token=session["access_token"])
+    return jsonify(resp.json()), resp.status_code
+
+
+@app.post("/api/admin/videos/<job_id>/cancel")
+@admin_required
+def api_admin_cancel_video(job_id: str):
+    resp = _api(
+        "POST", f"/admin/videos/{job_id}/cancel", token=session["access_token"])
+    return jsonify(resp.json()), resp.status_code
+
+
+@app.delete("/api/admin/videos/<job_id>")
+@admin_required
+def api_admin_delete_video(job_id: str):
+    resp = _api(
+        "DELETE", f"/admin/videos/{job_id}", token=session["access_token"])
+    return jsonify(resp.json()), resp.status_code
+
+
 # ── Profile ───────────────────────────────────────────────────────────────
 
 @app.route("/users/profile", methods=["GET", "POST"])