feat: MAINT-001 - Fix Ruff violations across all Python source

tests/test_gossip_and_relay.py

@@ -5,8 +5,7 @@ from __future__ import annotations
 import json
 import threading
 import time
-from pathlib import Path
-from unittest.mock import MagicMock, patch
+from unittest.mock import MagicMock
 
 
 # ---------------------------------------------------------------------------
@@ -277,7 +276,6 @@ def test_relay_server_peer_list_grows_on_connect():
 def test_relay_circuit_relay_proxies_message():
     "A node behind NAT (client_a) receives a message via circuit relay from client_b.\n\nTags: gossip, network, relay"
 
-    import websockets.sync.client  # type: ignore[import]
     from meshnet_relay.server import RelayServer
 
     relay = RelayServer(host="127.0.0.1", port=0)
@@ -755,7 +753,6 @@ def test_node_relay_bridge_reconnects_after_failed_connection(monkeypatch):
 
 def _start_tracker_and_register(extra_fields: dict) -> dict:
     """Helper: start tracker, register node with extra gossip fields, return response."""
-    import http.server
     import json as _json
     import urllib.request
 
@@ -766,7 +763,7 @@ def _start_tracker_and_register(extra_fields: dict) -> dict:
     url = f"http://127.0.0.1:{port}"
 
     payload = {
-        "endpoint": f"http://127.0.0.1:8001",
+        "endpoint": "http://127.0.0.1:8001",
         "shard_start": 0,
         "shard_end": 7,
         "model": "stub-model",

tests/test_mining_cli.py

@@ -5,8 +5,6 @@ from __future__ import annotations
 import json
 import socket
 import sys
-import types
-from pathlib import Path
 from unittest.mock import MagicMock, patch
 
 # A fake node server has no real backend to prove capability with; say so
@@ -134,7 +132,6 @@ def test_print_models_table_runs_without_error(capsys, monkeypatch):
 def test_wizard_writes_config_on_happy_path(tmp_path, monkeypatch):
     "Wizard writes config on happy path\n\nTags: general"
     from meshnet_node import wizard as wiz
-    from meshnet_node.config import load_config, save_config
 
     # Fake GPU
     gpus = [{"index": 0, "name": "RTX 4090", "vram_gb": 24.0, "backend": "cuda"}]
@@ -265,7 +262,6 @@ def test_config_command_no_config_exits_1(tmp_path, monkeypatch):
 
 def test_config_command_prints_saved_config(tmp_path, monkeypatch, capsys):
     "Config command prints saved config\n\nTags: general"
-    from meshnet_node import config as cfg_mod
     from meshnet_node.config import save_config
     from meshnet_node.cli import main
 
@@ -309,7 +305,6 @@ def test_detect_num_layers_returns_none_on_error(monkeypatch):
 def test_startup_auto_detects_shard_range(monkeypatch, tmp_path):
     "When shard_start/end are None, startup reads layer count from catalog.\n\nTags: general"
     from meshnet_node import startup as su
-    from meshnet_node.model_catalog import detect_num_layers
 
     calls = []
 

tests/test_openai_gateway.py

@@ -162,7 +162,7 @@ def test_streaming_end_to_end_http(two_node_setup):
         assert "text/event-stream" in content_type
         raw = resp.read().decode()
 
-    data_lines = [l for l in raw.strip().splitlines() if l.startswith("data: ")]
+    data_lines = [line for line in raw.strip().splitlines() if line.startswith("data: ")]
     assert data_lines, "No SSE data lines found"
     assert data_lines[-1] == "data: [DONE]"
 

tests/test_real_model_backend.py

@@ -13,7 +13,6 @@ import urllib.request
 import pytest
 
 from meshnet_node.model_backend import (
-    InsufficientVRAMError,
     PartialModelLoadUnsupported,
     KVCacheMiss,
     TensorPayload,

tests/test_settlement_loop.py

@@ -5,9 +5,7 @@ before the transaction is sent, unconfirmed batches resent by settlement id
 (never double-paying), banned wallets skipped, history queryable over HTTP.
 """
 
-import json
 import time
-import urllib.request
 
 import pytest
 
@@ -68,7 +66,7 @@ def test_threshold_triggers_payout_and_zeroes_pending():
     ledger.charge_request("client", MODEL, 1000, [("wallet-a", 12)])  # 0.018 pending
     treasury = _FakePayoutTreasury()
     tracker = _make_tracker(ledger, treasury, threshold=0.01)
-    port = tracker.start()
+    tracker.start()
     try:
         assert _wait_for(lambda: treasury.batches)
         assert treasury.batches[0] == [("wallet-a", pytest.approx(0.018))]

tests/test_tracker_consensus.py

@@ -157,7 +157,7 @@ def test_registration_on_follower_visible_on_all_nodes(three_tracker_cluster):
     _wait_until_follower_knows_leader(follower, timeout=2.0)
 
     # Register via a follower
-    node_id = _register_node(follower, port_hint=19999)
+    _register_node(follower, port_hint=19999)
 
     # Allow replication to propagate (Raft heartbeat interval is 50ms)
     time.sleep(0.5)
@@ -223,7 +223,7 @@ def test_registration_on_leader_visible_to_all(three_tracker_cluster):
     urls = list(urls)
 
     leader_url, followers = _wait_for_leader(urls, timeout=1.0)
-    node_id = _register_node(leader_url, port_hint=19996)
+    _register_node(leader_url, port_hint=19996)
 
     # Allow Raft heartbeat to replicate the entry
     time.sleep(0.3)

tests/test_tracker_routing.py

@@ -19,7 +19,6 @@ from meshnet_tracker.server import (
     TrackerServer,
     _NodeEntry,
     _available_quantizations,
-    _memory_pool_map,
     _rebalance_all_locked,
     _registration_ban_error,
     _scale_demanded_models_locked,
@@ -1448,7 +1447,7 @@ def test_tracker_pool_join_adds_redundant_copy_without_splitting_incumbent():
              "vram_bytes": 10_000, "ram_bytes": 10_000, "quantizations": ["bfloat16"],
              "benchmark_tokens_per_sec": 1.0, "hardware_profile": {}, "score": 1.0},
         )
-        second = _post_json(
+        _post_json(
             f"http://127.0.0.1:{tracker_port}/v1/nodes/register",
             {"endpoint": "http://127.0.0.1:9016", "model": "tiny-model",
              "vram_bytes": 10_000, "ram_bytes": 10_000, "quantizations": ["bfloat16"],