fix: use pyte+Rich hybrid for colored SVG screenshots

Screenshots now properly preserve terminal colors:
1. Replay buffer provides raw ANSI data with color codes
2. pyte interprets escape sequences for accurate screen state
3. Rich renders the pyte buffer with colors to SVG

This gives us both accurate terminal state (no creeping/wrapping)
and proper color preservation in screenshots.

Bumps version to 0.1.12.

tests/test_local_server_unit.py

@@ -195,6 +195,7 @@ class TestLocalServerHelpers:
 
         session = MagicMock()
         session.get_screen_lines = AsyncMock(return_value=["hello", ""])
+        session.get_replay_buffer = AsyncMock(return_value=b"hello\r\n")
 
         monkeypatch.setattr(server.session_manager, "get_session_by_route_key", lambda _rk: session)
 
@@ -213,6 +214,7 @@ class TestLocalServerHelpers:
 
         session = MagicMock()
         session.get_screen_lines = AsyncMock(return_value=["world", ""])
+        session.get_replay_buffer = AsyncMock(return_value=b"world\r\n")
 
         # Pretend app exists for slug "known"
         server.session_manager.apps_by_slug["known"] = App(
@@ -564,6 +566,7 @@ class TestLocalServerMoreCoverage:
 
         session = MagicMock()
         session.get_screen_lines = AsyncMock(return_value=["hello", ""])
+        session.get_replay_buffer = AsyncMock(return_value=b"hello\n")
         monkeypatch.setattr(server_with_no_apps.session_manager, "get_session_by_route_key", lambda _rk: session)
 
         resp = await server_with_no_apps._handle_screenshot(request)
@@ -735,14 +738,15 @@ class TestLocalServerMoreCoverage:
         assert created is True
 
     @pytest.mark.asyncio
-    async def test_handle_screenshot_uses_get_screen_lines(self, server_with_no_apps, monkeypatch):
-        """Test that screenshot uses get_screen_lines() from terminal session."""
+    async def test_handle_screenshot_uses_replay_buffer_with_pyte(self, server_with_no_apps, monkeypatch):
+        """Test that screenshot uses replay buffer with pyte for colored rendering."""
         request = MagicMock()
         request.query = {"route_key": "rk"}
         request.headers = {}
 
         session = MagicMock()
         session.get_screen_lines = AsyncMock(return_value=["line1", "line2", ""])
+        session.get_replay_buffer = AsyncMock(return_value=b"line1\r\nline2\r\n")
         monkeypatch.setattr(server_with_no_apps.session_manager, "get_session_by_route_key", lambda _rk: session)
 
         server_with_no_apps._route_last_activity["rk"] = 1.0
@@ -750,4 +754,4 @@ class TestLocalServerMoreCoverage:
         resp = await server_with_no_apps._handle_screenshot(request)
         assert resp.content_type == "image/svg+xml"
         assert "<svg" in resp.text
-        session.get_screen_lines.assert_awaited_once()
+        session.get_replay_buffer.assert_awaited_once()