feat: show optional SponsorBlock ranges on playback timeline

Checks/configuration.swift

@@ -130,6 +130,12 @@ struct ConfigurationChecks {
                     "built-in defaults hide buffer info, disable automatic quality, and enable snapping")
         try require(defaults.miruroVideoProvider.isEmpty && defaults.miruroCaptionProvider.isEmpty,
                     "Miruro defaults select automatic video and captions independently")
+        let sponsor = root.appendingPathComponent("sponsorblock.toml")
+        for enabled in [true, false] {
+            try Data("[playback]\nsponsorblock = \(enabled)\n".utf8).write(to: sponsor)
+            try require(try PlayerConfiguration.load(from: sponsor) == PlayerConfiguration(sponsorBlock: enabled),
+                        "SponsorBlock opt-in and explicit opt-out load without changing other defaults")
+        }
         let miruro = root.appendingPathComponent("miruro.toml")
         for (settings, video, captions) in [
             ("video_provider = \"new-Host_2\"", "new-Host_2", ""),
@@ -178,13 +184,15 @@ struct ConfigurationChecks {
             # Sections and nested keys can be quoted, with comments and whitespace.
             ['playback']
               'automatic_quality' = true
+              'sponsorblock' = true
             [ui]
             "buffer_info" = true # session display default
             compact_snap_to_edges = false
             """.utf8)
         try original.write(to: config)
         try files.setAttributes([.posixPermissions: 0o444], ofItemAtPath: config.path)
-        let configured = PlayerConfiguration(showBufferInfo: true, automaticQuality: true, snapToEdges: false)
+        let configured = PlayerConfiguration(showBufferInfo: true, automaticQuality: true, sponsorBlock: true,
+                                             snapToEdges: false)
         let environment = ["XDG_CONFIG_HOME": xdg.path]
         try require(try PlayerConfiguration.load(from: config) == configured,
                     "TOML comments, whitespace, quoted nested keys, and both boolean values load from a read-only file")
@@ -192,6 +200,7 @@ struct ConfigurationChecks {
         try require(session == configured, "application startup automatically loads the XDG config")
         session.showBufferInfo = false
         session.automaticQuality = false
+        session.sponsorBlock = false
         session.snapToEdges = true
         try require(session == defaults, "controls can override all settings within the session")
         try require(try Data(contentsOf: config) == original, "loading and session overrides do not change config bytes")
@@ -267,6 +276,10 @@ struct ConfigurationChecks {
             ("ui-legacy", "[ui]\nshow_buffer_info = true\n", ["ui.show_buffer_info"]),
             ("string", "[ui]\nbuffer_info = \"true\"\n", []),
             ("integer", "[playback]\nautomatic_quality = 1\n", []),
+            ("sponsor-string", "[playback]\nsponsorblock = \"true\"\n", ["sponsorblock"]),
+            ("sponsor-integer", "[playback]\nsponsorblock = 1\n", ["sponsorblock"]),
+            ("sponsor-array", "[playback]\nsponsorblock = [true]\n", ["sponsorblock"]),
+            ("sponsor-table", "[playback.sponsorblock]\nenabled = true\n", ["sponsorblock"]),
             ("array", "[ui]\ncompact_snap_to_edges = [true]\n", []),
             ("progress-value", "[ui]\ncompact_title_progress = \"unknown\"\n", ["compact_title_progress", "unknown"]),
             ("progress-bool", "[ui]\ncompact_title_progress = false\n", ["compact_title_progress"]),