Support audio, documents, stickers and video notes

Completes TODO #6. The bot accepted photo, animation, video, voice and
sticker; music files, documents and round videos were silently dropped.

- Replace the five near-identical media handlers with one dispatch table.
  Animations are matched before documents because Telegram populates
  both fields for a GIF, so the old ordering would have filed every GIF
  as a document once document support existed.
- Store video notes as "video". Telegram has no cached inline result for
  video notes, so this is what keeps round videos searchable; it costs
  the round presentation on playback.
- Build inline results from a table keyed by media_type, and cover audio
  and document. A test asserts every storable type has a builder, so a
  new media type cannot be added without a way to return it.
- Reuse one MEDIA_FILTER for both the idle and mid-keyword handlers;
  the second list had already drifted from the first.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

test_bot.py

@@ -0,0 +1,95 @@
+"""Media handling tests. Run with: python test_bot.py
+
+Covers the dispatch table that decides how an incoming message is stored and
+how it comes back through inline search.
+"""
+import datetime
+import os
+import sys
+
+os.environ.setdefault("BOT_TOKEN", "123456789:AAHtestTokenPlaceholder_ABCDEFGHIJKLMNOP")
+os.environ.setdefault("DB_PATH", ":memory:")
+sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))
+
+from aiogram.types import (Animation, Audio, Chat, Document, Message, PhotoSize,
+                           Sticker, Video, VideoNote, Voice)
+
+import bot as B
+
+CHAT = Chat(id=1, type="private")
+NOW = datetime.datetime.now()
+
+
+def msg(**kw) -> Message:
+    return Message(message_id=1, date=NOW, chat=CHAT, **kw)
+
+
+def sample_messages():
+    photo = PhotoSize(file_id="F_photo", file_unique_id="U_photo", width=1, height=1)
+    anim = Animation(file_id="F_gif", file_unique_id="U_gif", width=1, height=1, duration=1)
+    sticker = Sticker(file_id="F_st", file_unique_id="U_st", width=1, height=1,
+                      type="regular", is_animated=False, is_video=False)
+    return [
+        ("photo", msg(photo=[photo])),
+        # Telegram sets document alongside animation for backward compatibility.
+        ("gif", msg(animation=anim, document=Document(file_id="F_gif", file_unique_id="U_gif"))),
+        ("sticker", msg(sticker=sticker)),
+        ("video", msg(video=Video(file_id="F_v", file_unique_id="U_v", width=1, height=1, duration=1))),
+        ("video", msg(video_note=VideoNote(file_id="F_vn", file_unique_id="U_vn", length=1, duration=1))),
+        ("voice", msg(voice=Voice(file_id="F_vo", file_unique_id="U_vo", duration=1))),
+        ("audio", msg(audio=Audio(file_id="F_a", file_unique_id="U_a", duration=1))),
+        ("document", msg(document=Document(file_id="F_doc", file_unique_id="U_doc"))),
+    ]
+
+
+def test_every_type_extracts():
+    for expected, message in sample_messages():
+        found = B.extract_media(message)
+        assert found is not None, f"{expected}: nothing extracted"
+        assert found[0] == expected, f"expected {expected}, got {found[0]}"
+    print("  every supported media type extracts to the right media_type")
+
+
+def test_animation_beats_document():
+    gif = sample_messages()[1][1]
+    assert gif.document is not None, "test fixture should mimic Telegram's dual field"
+    assert B.extract_media(gif)[0] == "gif", "a GIF must not be filed as a document"
+    print("  animation wins over the backward-compat document field")
+
+
+def test_video_note_stored_as_video():
+    note = sample_messages()[4][1]
+    assert B.extract_media(note) == ("video", "F_vn", "U_vn")
+    print("  video notes are stored as video so inline search can return them")
+
+
+def test_non_media_ignored():
+    assert B.extract_media(msg(text="hello")) is None
+    print("  plain text messages are ignored")
+
+
+def test_every_stored_type_renders_inline():
+    stored = {t for t, _ in B.MEDIA_EXTRACTORS}
+    missing = stored - set(B.INLINE_BUILDERS)
+    assert not missing, f"stored but not renderable inline: {sorted(missing)}"
+    print("  every stored media_type has a matching inline builder")
+
+
+def test_builders_construct():
+    for media_type, build in B.INLINE_BUILDERS.items():
+        build("rid", f"FID_{media_type}", "cat, funny")
+        # Documents and videos require a non-empty title; keywords can be blank.
+        build("rid", f"FID_{media_type}", "")
+    print("  inline builders construct, including with empty keywords")
+
+
+def main():
+    for test in (test_every_type_extracts, test_animation_beats_document,
+                 test_video_note_stored_as_video, test_non_media_ignored,
+                 test_every_stored_type_renders_inline, test_builders_construct):
+        test()
+    print("\nAll media tests passed.")
+
+
+if __name__ == "__main__":
+    main()