fix(ego-lint): handle async arrow functions and GObject branch in check-init.py (#55)

## Summary

- Update `ARROW_FN_DEF` regex to include optional `async` keyword so
`const fn = async () => Main.panel.x` is not flagged
- Add `ARROW_FN_DEF` exemption to the `GOBJECT_CONSTRUCTORS` branch so
`const make = () => new St.Label()` at module scope is not flagged
- Add test fixture cases and assertions for both scenarios

Closes #45

## Test plan

- [x] `python3 check-init.py` correctly flags only the true violation
(line 5) and exempts all arrow function lines
- [x] Full test suite passes (561 assertions)

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

Author: ZviBaratz

skills/ego-lint/scripts/check-init.py

@@ -65,6 +65,7 @@ def is_skip_line(line):
 # module scope).  Detect `const fn = (...) => expr` patterns.
 ARROW_FN_DEF = re.compile(
     r'(?:const|let|var)\s+\w+\s*=\s*'   # variable assignment
+    r'(?:async\s+)?'                      # optional async keyword
     r'(?:\([^)]*\)|\w+)'                 # parameter list or single param
     r'\s*=>'                              # arrow
 )
@@ -198,6 +199,10 @@ def check_init_modifications(ext_dir):
                     continue
                 violations.append(f"{rel}:{lineno}")
             elif GOBJECT_CONSTRUCTORS.search(line):
+                # Arrow function definitions are lazy — not executed at
+                # module scope
+                if ARROW_FN_DEF.search(line):
+                    continue
                 # GObject.registerClass() returns a class, not an instance
                 if not REGISTER_CLASS.search(line) and \
                         not VALUE_TYPES.search(line):

tests/fixtures/init-time-safety@test/extension.js

@@ -7,6 +7,12 @@ const primaryIdx = Main.layoutManager.primaryIndex;
 // OK: arrow function definition is lazy (body not executed at module scope)
 const getMonitors = () => Main.layoutManager.monitors;
 
+// OK: async arrow function definition is lazy
+const addItem = async () => Main.panel.addToStatusArea('test', null);
+
+// OK: arrow function wrapping GObject constructor
+const makeLabel = () => new St.Label({text: 'hello'});
+
 export default class InitTimeTest extends Extension {
     enable() {
         // OK: Shell globals inside enable()

tests/run-tests.sh

@@ -217,6 +217,8 @@ assert_exit_code "exits with 1 (has module-scope violation)" 1
 assert_output_contains "fails on module-scope Main access" "\[FAIL\].*init/shell-modification"
 assert_output_not_contains "no FP on helper constructor" "init/shell-modification.*helper.js"
 assert_output_not_contains "no FP on arrow function definition" "init/shell-modification.*extension.js:8"
+assert_output_not_contains "no FP on async arrow function" "init/shell-modification.*extension.js:11"
+assert_output_not_contains "no FP on arrow GObject constructor" "init/shell-modification.*extension.js:14"
 echo ""
 
 # --- lifecycle-imbalance ---