chore: smoke test fixes and code quality improvements (#88)

* fix: replace deprecated datetime.utcnow() and websockets.legacy APIs

- Replace datetime.utcnow() with datetime.now(UTC) in Orderbook model
- Use websockets.asyncio.client.connect instead of legacy websockets.connect
- Import ConnectionClosed from websockets.exceptions directly
- Update test mocks to patch the new import paths

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

* fix: resolve ruff lint errors in alembic migration

- Replace typing.Union with X | Y syntax (UP007)
- Import Sequence from collections.abc instead of typing (UP035)

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

* fix: remove deprecated version key from docker-compose.yml

The top-level 'version' key is obsolete in modern Docker Compose
and produces a warning.

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

* docs: fix README to match actual project structure and tooling

- Replace pip commands with uv equivalents
- Fix run command from 'python -m src.main' to 'python -m polymarket_insider_tracker'
- Update project structure tree to reflect actual src/polymarket_insider_tracker/ layout

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

---------

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

src/polymarket_insider_tracker/ingestor/models.py

@@ -86,7 +86,7 @@ class Orderbook:
     bids: tuple[OrderbookLevel, ...]
     asks: tuple[OrderbookLevel, ...]
     tick_size: Decimal
-    timestamp: datetime = field(default_factory=datetime.utcnow)
+    timestamp: datetime = field(default_factory=lambda: datetime.now(UTC))
 
     @classmethod
     def from_clob_orderbook(cls, orderbook: Any) -> "Orderbook":

src/polymarket_insider_tracker/ingestor/websocket.py

@@ -9,8 +9,9 @@ from dataclasses import dataclass
 from enum import Enum
 from typing import Any
 
-import websockets
 from websockets.asyncio.client import ClientConnection
+from websockets.asyncio.client import connect as ws_connect
+from websockets.exceptions import ConnectionClosed
 
 from polymarket_insider_tracker.ingestor.models import TradeEvent
 
@@ -156,7 +157,7 @@ class TradeStreamHandler:
         await self._set_state(ConnectionState.CONNECTING)
 
         try:
-            ws = await websockets.connect(
+            ws = await ws_connect(
                 self._host,
                 ping_interval=self._ping_interval,
                 ping_timeout=self._ping_interval * 2,
@@ -227,7 +228,7 @@ class TradeStreamHandler:
                 else:
                     logger.debug("Received binary message (%d bytes)", len(message))
 
-        except websockets.ConnectionClosed as e:
+        except ConnectionClosed as e:
             logger.warning("Connection closed: %s", e)
             raise
         except Exception as e:
@@ -284,7 +285,7 @@ class TradeStreamHandler:
             while self._running:
                 try:
                     await self._listen(self._ws)
-                except (websockets.ConnectionClosed, Exception) as e:
+                except (ConnectionClosed, Exception) as e:
                     if not self._running:
                         break