ci: run mypy against the installed package, fix what that exposed

The lint job failed on its first run with three errors my local run had not
shown. Cause: locally mypy had no xknxproject installed, so ignore_missing_imports
hid every mismatch against that library's own TypedDicts. CI installs the package
and therefore sees them.

The two range-walk helpers took dict[str, Any] but are handed a GroupRange
TypedDict, which mypy rejects because dict is invariant; they take Mapping now,
which is what they actually use. suggest passes the raw parsed dict into
build_loaded_from_raw, whose parameter is KNXProject, so the boundary is an
explicit cast rather than a widened public signature.

CONTRIBUTING now gives the command that matches CI, with the reason, so the next
person does not get a clean local run and a red CI.

Suite passes, corpus guard reports no drift.

CONTRIBUTING.md

@@ -59,6 +59,17 @@ pip install -e .
 python tests/test_pipeline.py
 ```
 
+### Lint and types
+
+```bash
+ruff check nickol_knx_mcp tests tools
+uvx --with-editable . mypy        # the package must be installed, or mypy misses xknxproject's types
+```
+
+Run mypy with the package installed. Without it, `ignore_missing_imports` silently hides every
+mismatch against xknxproject's own TypedDicts, and CI, which does install it, will disagree.
+Ruff is configured to `E9,F` only: real errors, no style rules.
+
 CI runs the smoke test on Python 3.10–3.12 for every push and PR.
 
 ### Local corpus guard

nickol_knx_mcp/generate_ets.py

@@ -12,6 +12,7 @@ from __future__ import annotations
 
 import csv
 import io
+from collections.abc import Mapping
 from typing import Any
 from xml.sax.saxutils import escape
 
@@ -28,7 +29,7 @@ def _hierarchy(project: LoadedProject) -> dict[int, dict[str, Any]]:
     main_names: dict[int, str] = {}
     mid_names: dict[tuple[int, int], str] = {}
 
-    def walk(rng: dict[str, Any]) -> None:
+    def walk(rng: Mapping[str, Any]) -> None:
         start = rng.get("address_start")
         name = rng.get("name", "")
         if isinstance(start, int):

nickol_knx_mcp/project.py

@@ -9,6 +9,7 @@ from __future__ import annotations
 
 import re
 from dataclasses import dataclass, field
+from collections.abc import Mapping
 from typing import Any, Optional
 
 from xknxproject import XKNXProj
@@ -293,7 +294,7 @@ def _build_range_name_map(raw: KNXProject) -> dict[str, str]:
     """
     out: dict[str, str] = {}
 
-    def walk(rng: dict[str, Any], depth: int) -> None:
+    def walk(rng: Mapping[str, Any], depth: int) -> None:
         start = rng.get("address_start")
         name = rng.get("name", "")
         if isinstance(start, int):

nickol_knx_mcp/suggest.py

@@ -27,7 +27,7 @@ from __future__ import annotations
 
 import re
 from collections import defaultdict
-from typing import Any, Optional
+from typing import Any, Optional, cast
 
 import yaml
 
@@ -583,7 +583,8 @@ def _device_of(project: dict[str, Any], ga: str) -> tuple[str, str]:
 
 
 def _fallback_suggestions(project: dict[str, Any], covered: set[str]) -> list[dict[str, Any]]:
-    loaded = build_loaded_from_raw(project, project.get("info", {}).get("name") or "project.knxproj")
+    loaded = build_loaded_from_raw(cast("Any", project),
+                                   project.get("info", {}).get("name") or "project.knxproj")
     res = generate_ha_yaml(loaded)
     doc = yaml.safe_load(res["yaml"]) or {}
     knx = doc.get("knx") or {}