#193 Add --set/--season overrides for batch episode renaming

--season auto-numbers episodes (E01, E02, ...) across a directory;
--set TYPE=VALUE overrides any parsed chunk, e.g. forcing name when
release text buries it in noise. Requires splitting SxxExx tokens
into separate season/episode chunks (previously one glued value)
and rejoining them without a separator in the generated name.

Also scopes --season numbering per directory instead of the whole
tree, drops leftover unknown text when overriding name on titles
with nothing else recognized, and makes extension matching
case-insensitive.

tests/test_process_path.py

@@ -0,0 +1,100 @@
+import os
+import tempfile
+import unittest
+
+from renamer import CliAction, _is_media_file, process_path
+
+
+class TestIsMediaFile(unittest.TestCase):
+    def test_extension_is_case_insensitive(self):
+        self.assertTrue(_is_media_file("Show.S04E06.MKV"))
+        self.assertTrue(_is_media_file("Show.S04E06.mkv"))
+        self.assertTrue(_is_media_file("Show.S04E06.AVI"))
+
+    def test_unsupported_extension(self):
+        self.assertFalse(_is_media_file("Show.S04E06.txt"))
+
+
+class TestRenameCaseInsensitiveExtension(unittest.TestCase):
+    def test_uppercase_extension_is_processed(self):
+        with tempfile.TemporaryDirectory() as root:
+            original = "Show S04E06.MKV"
+            open(os.path.join(root, original), "w").close()
+
+            process_path(CliAction.rename, os.path.join(root, original))
+
+            self.assertEqual(os.listdir(root), ["Show.S04E06.MKV"])
+
+
+class TestSeasonNumbering(unittest.TestCase):
+    def test_scoped_to_directory_not_whole_tree(self):
+        with tempfile.TemporaryDirectory() as root:
+            season_dir = os.path.join(root, "Season 1")
+            extras_dir = os.path.join(root, "Extras")
+            os.mkdir(season_dir)
+            os.mkdir(extras_dir)
+            for name in (
+                "Show.(01.serija.iz.10).mkv",
+                "Show.(02.serija.iz.10).mkv",
+            ):
+                open(os.path.join(season_dir, name), "w").close()
+            open(os.path.join(extras_dir, "Blooper.reel.mkv"), "w").close()
+
+            process_path(
+                CliAction.rename, root, overrides={"name": "Show"}, season=1,
+            )
+
+            self.assertEqual(
+                sorted(os.listdir(season_dir)),
+                ["Show.S01E01.mkv", "Show.S01E02.mkv"],
+            )
+            # Extras is a separate directory: it gets its own numbering,
+            # starting fresh at E01, instead of continuing the season's count.
+            self.assertEqual(os.listdir(extras_dir), ["Show.S01E01.mkv"])
+
+    def test_single_file_target_defaults_to_episode_one(self):
+        with tempfile.TemporaryDirectory() as root:
+            original = "Show.(01.serija.iz.10).mkv"
+            open(os.path.join(root, original), "w").close()
+
+            process_path(
+                CliAction.rename, os.path.join(root, original),
+                overrides={"name": "Show"}, season=1,
+            )
+
+            self.assertEqual(os.listdir(root), ["Show.S01E01.mkv"])
+
+
+class TestSetOverride(unittest.TestCase):
+    def test_name_override_drops_unrecognized_leftovers(self):
+        with tempfile.TemporaryDirectory() as root:
+            # nothing else in the title is recognized (no year/quality/etc),
+            # so it would otherwise land entirely under "unknown"
+            original = "Show.(01.serija.iz.10).mkv"
+            open(os.path.join(root, original), "w").close()
+
+            process_path(
+                CliAction.rename, os.path.join(root, original),
+                overrides={"name": "Show"}, season=1,
+            )
+
+            self.assertEqual(os.listdir(root), ["Show.S01E01.mkv"])
+
+    def test_name_override_preserves_unknown_when_name_was_recognized(self):
+        with tempfile.TemporaryDirectory() as root:
+            original = "The.Walking.Dead.S04E06.1080p.WEB-DL.Rus.Eng.HDCLUB.mkv"
+            open(os.path.join(root, original), "w").close()
+
+            process_path(
+                CliAction.rename, os.path.join(root, original),
+                overrides={"name": "TWD"},
+            )
+
+            self.assertEqual(
+                os.listdir(root),
+                ["TWD.S04E06.1080p.WEB-DL.Rus.Eng.HDCLUB.mkv"],
+            )
+
+
+if __name__ == "__main__":
+    unittest.main()