chore: make the ruff config load, and fix what it then reports

pyproject.toml used `target_version`, which modern ruff rejects as an unknown
field -- so ruff failed to parse the config and linted nothing at all. Renaming
it to `target-version` surfaced 17 violations.

- Move `select`/`ignore`/`fixable`/`unfixable`/`dummy-variable-rgx`/`mccabe`
  under `[tool.ruff.lint]`, where they now belong.
- Exclude app/external/result_type/*, which is vendored third-party code kept
  close to upstream, alongside the already-excluded generated protos. That
  accounts for 7 of the 17.
- Add per-file E501 ignores for app/apps/docs.py and
  app/system/impl/native_python.py: their long lines are verbatim example
  payloads (sample API error bodies, a Nix config snippet) and re-wrapping them
  would misrepresent what they document.
- Wrap three genuinely long lines, drop an unused import and an unused local,
  and give app/apps/tasks_impl/__init__.py an __all__ for its re-exports.

ruff check now passes under both the pinned 0.14.14 and current nixpkgs ruff.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Author: fusion44

app/apps/cache.py

@@ -113,7 +113,8 @@ async def set_cached_app_status(
                     return Err(e)
 
             logger.debug(
-                f"App status cache updated. Key: {AppsServiceKeys.APP_STATUS_MESSAGE_KEY}"
+                "App status cache updated. Key: "
+                f"{AppsServiceKeys.APP_STATUS_MESSAGE_KEY}"
             )
 
             return Ok(None)

app/apps/tasks_impl/__init__.py

@@ -1,2 +1,4 @@
 from .app_manage import app_manage_task_impl
 from .app_status_update import update_app_state_task_impl
+
+__all__ = ["app_manage_task_impl", "update_app_state_task_impl"]

app/lightning/models.py

@@ -733,7 +733,8 @@ def _features(features):
 
     @classmethod
     def from_cln_json(cls, i) -> "Invoice":
-        # Handle missing amount_msat field (e.g., in BOLT12 offers or certain invoice types)
+        # Handle missing amount_msat field (e.g., in BOLT12 offers or
+        # certain invoice types)
         # Use amount_received_msat if amount_msat is not present and invoice is paid
         amt = 0
         if "amount_msat" in i:

app/lightning/service.py

@@ -211,7 +211,6 @@ async def register_lightning_listener():
 
 async def _handle_info_listener():
     last_info = None
-    last_info_lite = None
     while True:
         info = await ln.get_ln_info()
 

app/system/router.py

@@ -145,7 +145,10 @@ async def get_system_health(
     response: Response,
     verbose: bool = Query(
         False,
-        description="If true, include a per-subsystem (api, bitcoind, lightning) health breakdown.",
+        description=(
+            "If true, include a per-subsystem (api, bitcoind, lightning) "
+            "health breakdown."
+        ),
     ),
 ) -> SystemHealthInfo:
     result = await system_health(verbose)

pyproject.toml

@@ -55,14 +55,6 @@ build-backend = "hatchling.build"
 profile = "black"
 
 [tool.ruff]
-# Enable pycodestyle (`E`) and Pyflakes (`F`) codes by default.
-select = ["E", "F"]
-ignore = []
-
-# Allow auto fix for all enabled rules (when `--fix`) is provided.
-fixable = ["A", "B", "C", "D", "E", "F", "G", "I", "N", "Q", "S", "T", "W", "ANN", "ARG", "BLE", "COM", "DJ", "DTZ", "EM", "ERA", "EXE", "FBT", "ICN", "INP", "ISC", "NPY", "PD", "PGH", "PIE", "PL", "PT", "PTH", "PYI", "RET", "RSE", "RUF", "SIM", "SLF", "TCH", "TID", "TRY", "UP", "YTT"]
-unfixable = []
-
 # Exclude a variety of commonly ignored directories.
 exclude = [
     ".bzr",
@@ -86,18 +78,36 @@ exclude = [
     "dist",
     "node_modules",
     "venv",
-    "app/lightning/impl/protos/*"
+    # generated from the LND/CLN .proto files
+    "app/lightning/impl/protos/*",
+    # vendored third-party Result type, kept close to upstream
+    "app/external/result_type/*",
 ]
 
 # Same as Black.
 line-length = 88
 
+target-version = "py311"
+
+[tool.ruff.lint]
+# Enable pycodestyle (`E`) and Pyflakes (`F`) codes by default.
+select = ["E", "F"]
+ignore = []
+
+# Allow auto fix for all enabled rules (when `--fix`) is provided.
+fixable = ["A", "B", "C", "D", "E", "F", "G", "I", "N", "Q", "S", "T", "W", "ANN", "ARG", "BLE", "COM", "DJ", "DTZ", "EM", "ERA", "EXE", "FBT", "ICN", "INP", "ISC", "NPY", "PD", "PGH", "PIE", "PL", "PT", "PTH", "PYI", "RET", "RSE", "RUF", "SIM", "SLF", "TCH", "TID", "TRY", "UP", "YTT"]
+unfixable = []
+
 # Allow unused variables when underscore-prefixed.
 dummy-variable-rgx = "^(_+|(_+[a-zA-Z0-9_]*[a-zA-Z0-9]+?))$"
 
-target_version = "py311"
+[tool.ruff.lint.per-file-ignores]
+# Long lines here are verbatim example payloads (sample API error bodies, a Nix
+# config snippet). Wrapping them would misrepresent what they document.
+"app/apps/docs.py" = ["E501"]
+"app/system/impl/native_python.py" = ["E501"]
 
-[tool.ruff.mccabe]
+[tool.ruff.lint.mccabe]
 # Unlike Flake8, default to a complexity level of 10.
 max-complexity = 10
 

tests/test_ws_manager.py

@@ -1,7 +1,6 @@
 import asyncio
 import json
 
-import pytest
 from starlette.websockets import WebSocketDisconnect
 
 from app.api.ws_manager import WebSocketManager