fix: escape LIKE metacharacters in startsWith; add lessThan test

Music/Services/DatabaseService.swift

@@ -499,8 +499,12 @@ nonisolated final class DatabaseService: Sendable {
                 fragments.append("LOWER(\(col)) = LOWER(?)")
                 args.append(s)
             case (.startsWith, .string(let s)):
-                fragments.append("LOWER(\(col)) LIKE LOWER(?) || '%'")
-                args.append(s)
+                let escaped = s
+                    .replacingOccurrences(of: "\\", with: "\\\\")
+                    .replacingOccurrences(of: "%",  with: "\\%")
+                    .replacingOccurrences(of: "_",  with: "\\_")
+                fragments.append("LOWER(\(col)) LIKE LOWER(?) || '%' ESCAPE '\\'")
+                args.append(escaped)
             case (.equals, .int(let i)):
                 fragments.append("\(col) = ?"); args.append(i)
             case (.greaterThan, .int(let i)):

MusicTests/SmartPlaylistTests.swift

@@ -248,6 +248,25 @@ struct SmartPlaylistTests {
         }
     }
 
+    // Verifies that lessThan on an integer field returns only tracks strictly
+    // below the threshold value.
+    @Test func fetchTracksWithLessThanCondition() throws {
+        // Step 1: Insert tracks with years 1990, 2010, 2020
+        // Step 2: Fetch with year < 2000
+        // Step 3: Verify only the 1990 track is returned
+        let db = try DatabaseService(inMemory: true)
+        var t1 = Track.fixture(fileURL: "/a.mp3", year: 1990)
+        var t2 = Track.fixture(fileURL: "/b.mp3", year: 2010)
+        var t3 = Track.fixture(fileURL: "/c.mp3", year: 2020)
+        try db.insert(&t1)
+        try db.insert(&t2)
+        try db.insert(&t3)
+        let conditions = [SmartPlaylistCondition(field: .year, op: .lessThan, value: .int(2000))]
+        let results = try db.fetchTracks(conditions: conditions, sortColumn: "title", ascending: true)
+        #expect(results.count == 1)
+        #expect((results[0].year ?? 0) < 2000)
+    }
+
     // Updates the conditions of a structured smart playlist and verifies the updated
     // conditions are persisted and fetch back correctly.
     @Test func updateSmartPlaylistConditionsPersists() throws {