feat: initial IRC bouncer implementation

Async Python IRC bouncer with SOCKS5 proxy support, multi-network
connections, password auth, and persistent SQLite backlog with replay.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/test_backlog.py

@@ -0,0 +1,89 @@
+"""Tests for SQLite backlog storage."""
+
+import tempfile
+from pathlib import Path
+
+import pytest
+
+from bouncer.backlog import Backlog
+
+
+@pytest.fixture
+async def backlog():
+    db_path = Path(tempfile.mktemp(suffix=".db"))
+    bl = Backlog(db_path)
+    await bl.open()
+    yield bl
+    await bl.close()
+    db_path.unlink(missing_ok=True)
+
+
+class TestBacklog:
+    async def test_store_and_replay(self, backlog: Backlog):
+        msg_id = await backlog.store("libera", "#test", "nick", "PRIVMSG", "hello")
+        assert msg_id > 0
+
+        entries = await backlog.replay("libera")
+        assert len(entries) == 1
+        assert entries[0].content == "hello"
+        assert entries[0].sender == "nick"
+        assert entries[0].target == "#test"
+
+    async def test_replay_since_id(self, backlog: Backlog):
+        id1 = await backlog.store("libera", "#test", "a", "PRIVMSG", "first")
+        id2 = await backlog.store("libera", "#test", "b", "PRIVMSG", "second")
+        id3 = await backlog.store("libera", "#test", "c", "PRIVMSG", "third")
+
+        entries = await backlog.replay("libera", since_id=id1)
+        assert len(entries) == 2
+        assert entries[0].id == id2
+        assert entries[1].id == id3
+
+    async def test_replay_empty(self, backlog: Backlog):
+        entries = await backlog.replay("nonexistent")
+        assert entries == []
+
+    async def test_network_isolation(self, backlog: Backlog):
+        await backlog.store("libera", "#test", "a", "PRIVMSG", "libera msg")
+        await backlog.store("oftc", "#test", "b", "PRIVMSG", "oftc msg")
+
+        libera = await backlog.replay("libera")
+        oftc = await backlog.replay("oftc")
+        assert len(libera) == 1
+        assert len(oftc) == 1
+        assert libera[0].content == "libera msg"
+        assert oftc[0].content == "oftc msg"
+
+    async def test_mark_and_get_last_seen(self, backlog: Backlog):
+        assert await backlog.get_last_seen("libera") == 0
+
+        await backlog.mark_seen("libera", 42)
+        assert await backlog.get_last_seen("libera") == 42
+
+        await backlog.mark_seen("libera", 100)
+        assert await backlog.get_last_seen("libera") == 100
+
+    async def test_prune(self, backlog: Backlog):
+        for i in range(10):
+            await backlog.store("libera", "#test", "n", "PRIVMSG", f"msg{i}")
+
+        deleted = await backlog.prune("libera", keep=3)
+        assert deleted == 7
+
+        entries = await backlog.replay("libera")
+        assert len(entries) == 3
+        assert entries[0].content == "msg7"
+
+    async def test_prune_zero_keeps_all(self, backlog: Backlog):
+        for i in range(5):
+            await backlog.store("libera", "#test", "n", "PRIVMSG", f"msg{i}")
+
+        deleted = await backlog.prune("libera", keep=0)
+        assert deleted == 0
+        assert len(await backlog.replay("libera")) == 5
+
+    async def test_record_disconnect(self, backlog: Backlog):
+        await backlog.store("libera", "#test", "n", "PRIVMSG", "msg")
+        await backlog.record_disconnect("libera")
+        last = await backlog.get_last_seen("libera")
+        assert last > 0