fix(ci): use .clang-format file in CI and set AllowShortFunctionsOnASingleLine: None

- Switch CI clang-format-18 check from --style=Google to --style=file
  so it reads the repo's .clang-format instead of raw Google defaults.
  This eliminates version-skew between clang-format-18 (CI) and
  clang-format-21 (local pre-commit hook).
- Change AllowShortFunctionsOnASingleLine from Empty to None in
  .clang-format so short function bodies (including empty {}) are
  always expanded to multi-line, ensuring v18 and v21 agree.
- Re-format irk_capture.h: expand setup() override {} to multi-line.

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

Author: DerekSeaman

.clang-format

@@ -23,7 +23,7 @@ SpacesInContainerLiterals: true
 # ESP-IDF specific: Do not alphabetize headers
 SortIncludes: false
 
-# Clean up empty functions/blocks
-AllowShortFunctionsOnASingleLine: Empty
+# Never collapse function bodies to single line
+AllowShortFunctionsOnASingleLine: None
 KeepEmptyLinesAtTheStartOfBlocks: false
 ---

.github/workflows/lint.yml

@@ -41,7 +41,7 @@ jobs:
       - name: C++ Format Check
         run: |
           find components -name '*.cpp' -o -name '*.h' | \
-            xargs clang-format-18 --style=Google --dry-run --Werror
+            xargs clang-format-18 --style=file --dry-run --Werror
 
       # 3. Python Lint
       - name: Python Lint

components/irk_capture/irk_capture.h

@@ -67,7 +67,8 @@ class IRKCaptureText : public text::Text, public Component {
 // Text sensor for IRK/Address output
 class IRKCaptureTextSensor : public text_sensor::TextSensor, public Component {
  public:
-  void setup() override {}
+  void setup() override {
+  }
   void dump_config() override;
 };