diff --git a/backend/apps/agents/browser/runner.py b/backend/apps/agents/browser/runner.py
index 40a70868..de3fd131 100644
--- a/backend/apps/agents/browser/runner.py
+++ b/backend/apps/agents/browser/runner.py
@@ -65,7 +65,7 @@ async def run_browser_agent(
     await ws_manager.emit_message(session_id, user_msg)
 
     try:
-        for turn in range(MAX_TURNS):
+        for _ in range(MAX_TURNS):
             if cancel_event.is_set():
                 break
             response = await client.messages.create(
diff --git a/backend/apps/agents/browser_mcp_server.py b/backend/apps/agents/browser_mcp_server.py
index 8878889f..a26e8e7d 100644
--- a/backend/apps/agents/browser_mcp_server.py
+++ b/backend/apps/agents/browser_mcp_server.py
@@ -36,15 +36,6 @@ def send_response(id_, result=None, error=None):
     sys.stdout.write(json.dumps(msg) + "\n")
     sys.stdout.flush()
 
-
-def send_notification(method, params=None):
-    msg = {"jsonrpc": "2.0", "method": method}
-    if params is not None:
-        msg["params"] = params
-    sys.stdout.write(json.dumps(msg) + "\n")
-    sys.stdout.flush()
-
-
 def call_backend(action: str, browser_id: str, params: dict | None = None, tab_id: str = "") -> dict:
     payload = json.dumps({
         "action": action,
diff --git a/backend/apps/analytics/collector.py b/backend/apps/analytics/collector.py
index 75fa7764..88b54eb4 100644
--- a/backend/apps/analytics/collector.py
+++ b/backend/apps/analytics/collector.py
@@ -62,16 +62,6 @@ def _get_installation_id() -> str:
         _installation_id = uuid4().hex
     return _installation_id
 
-
-def _is_opted_in() -> bool:
-    """Check if user has opted in to analytics."""
-    try:
-        from backend.apps.settings.settings import load_settings
-        return getattr(load_settings(), "analytics_opt_in", True)
-    except Exception:
-        return True
-
-
 def record(
     event_type: str,
     properties: dict | None = None,
@@ -115,9 +105,4 @@ def identify(extra_properties: dict | None = None):
             },
         )
     except Exception as e:
-        logger.debug(f"PostHog identify failed (non-critical): {e}")
-
-
-def get_collector():
-    """Backward compat — returns None since we no longer have a local collector."""
-    return None
+        logger.debug(f"PostHog identify failed (non-critical): {e}")
\ No newline at end of file
diff --git a/backend/apps/common/model_registry.py b/backend/apps/common/model_registry.py
index 3e9fcb5d..450f390d 100644
--- a/backend/apps/common/model_registry.py
+++ b/backend/apps/common/model_registry.py
@@ -24,7 +24,7 @@ class ModelDef:
 # fmt: off
 ALL_MODELS: list[ModelDef] = [
     # Anthropic
-    ModelDef("sonnet",  "Claude Sonnet 4.6", "claude-sonnet-4-6",  "Anthropic", "anthropic", 1_000_000, 3.0,  15.0),
+    ModelDef("sonnet", label="Claude Sonnet 4.6", model_id="claude-sonnet-4-6",  provider="Anthropic", api="anthropic", context_window=1_000_000, input_cost_per_1m=3.0, output_cost_per_1m=15.0),
     ModelDef("opus",    "Claude Opus 4.6",   "claude-opus-4-6",    "Anthropic", "anthropic", 1_000_000, 5.0,  25.0),
     ModelDef("haiku",   "Claude Haiku 4.5",  "claude-haiku-4-5",   "Anthropic", "anthropic",   200_000, 1.0,   5.0),
     # OpenAI
diff --git a/backend/config/paths.py b/backend/config/paths.py
index 083ebdfb..4a96a9a7 100644
--- a/backend/config/paths.py
+++ b/backend/config/paths.py
@@ -34,6 +34,4 @@ OUTPUTS_DIR = os.path.join(DATA_ROOT, "outputs")
 OUTPUTS_WORKSPACE_DIR = os.path.join(DATA_ROOT, "outputs_workspace")
 SKILLS_WORKSPACE_DIR = os.path.join(DATA_ROOT, "skills_workspace")
 DASHBOARD_LAYOUT_DIR = os.path.join(DATA_ROOT, "dashboard_layout")
-BUILTIN_PERMISSIONS_PATH = os.path.join(DATA_ROOT, "builtin_permissions.json")
-
-BACKEND_DIR = _BACKEND_DIR
+BUILTIN_PERMISSIONS_PATH = os.path.join(DATA_ROOT, "builtin_permissions.json")
\ No newline at end of file
diff --git a/backend/main.py b/backend/main.py
index 17bd4ae9..2ed9c0e2 100644
--- a/backend/main.py
+++ b/backend/main.py
@@ -41,8 +41,6 @@ app.add_middleware(
     allow_headers=["*"],
 )
 
-x = 1
-
 @app.websocket("/ws/agents/{session_id}")
 async def websocket_session(websocket: WebSocket, session_id: str):
     await ws_manager.connect_session(session_id, websocket)
diff --git a/backend/ports.py b/backend/ports.py
index 7d9c74e9..cc690a6d 100644
--- a/backend/ports.py
+++ b/backend/ports.py
@@ -12,8 +12,6 @@ with open(_config_path) as _f:
     _cfg = json.load(_f)
 
 BACKEND_DEV_PORT: int = _cfg["backend"]["dev"]
-BACKEND_PROD_PORT: int = _cfg["backend"]["prod"]
-FRONTEND_DEV_PORT: int = _cfg["frontend"]["dev"]
 NINE_ROUTER_DEV_PORT: int = _cfg["nineRouter"]["dev"]
 NINE_ROUTER_PROD_PORT: int = _cfg["nineRouter"]["prod"]
 
diff --git a/backend/tests/test_analytics.py b/backend/tests/test_analytics.py
index e412f3c6..54ecf008 100644
--- a/backend/tests/test_analytics.py
+++ b/backend/tests/test_analytics.py
@@ -9,13 +9,10 @@ Run with:
     cd backend && python -m pytest tests/test_analytics.py -v
 """
 
-import asyncio
 import json
 import os
-import sys
 import tempfile
-from datetime import datetime, timedelta
-from unittest.mock import AsyncMock, MagicMock, patch, call
+from unittest.mock import MagicMock
 from uuid import uuid4
 
 import pytest