feat: Add movie playback progress tracking

Co-authored-by: mathieumoran1 <[email protected]>

models/PlaybackProgress.js

@@ -0,0 +1,20 @@
+const mongoose = require("mongoose");
+
+const playbackProgressSchema = new mongoose.Schema(
+  {
+    userId: { type: mongoose.Schema.Types.ObjectId, ref: "User", required: true, index: true },
+    movieId: { type: mongoose.Schema.Types.ObjectId, ref: "Movie", required: true, index: true },
+    // seconds
+    time: { type: Number, default: 0 },
+    // seconds (optional, best-effort from the client)
+    duration: { type: Number, default: null },
+    updatedAt: { type: Date, default: Date.now },
+  },
+  { versionKey: false }
+);
+
+// One progress row per user + movie
+playbackProgressSchema.index({ userId: 1, movieId: 1 }, { unique: true });
+
+module.exports = mongoose.model("PlaybackProgress", playbackProgressSchema);
+