fix(ego-lint): correct R-SLOP-24 guard docs and add missing exit-code assertion

- Fix inaccurate claim that quote prefix avoids matching `desktop.png` —
  it actually avoids property-access contexts like `this.desktop.theme`
- Add assert_exit_code to system-schema-bare test block for consistency
- Broaden assertion label to cover all three guard mechanisms tested

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

Author: ZviBaratz

skills/ego-lint/references/rules-reference.md

@@ -2233,7 +2233,7 @@ Rules for APIs removed or changed in specific GNOME Shell versions. These rules
 - **Rule**: `new Gio.Settings()` should not be used in GNOME 45+ extensions.
 - **Rationale**: The `Extension` base class provides `this.getSettings()` which uses the correct schema path automatically. Manually constructing `Gio.Settings` requires specifying the schema ID and may use the wrong compiled schema path.
 - **Fix**: Use `this.getSettings()` in the Extension subclass, or pass a schema ID: `this.getSettings('org.gnome.shell.extensions.my-ext')`.
-- **Guard**: Suppressed when `schema.*org.gnome.` (excluding `shell.extensions.`), string-literal-anchored system schema substrings (`'desktop.` or `"desktop.`), bare `shell.app-switcher`, or enumerated system-schema constants (`KEYBINDINGS_SCHEMA`, `NOTIFICATIONS_SCHEMA`, `DESKTOP_SCHEMA`, `INTERFACE_SCHEMA`, `WM_SCHEMA`, `MUTTER_SCHEMA`, `APP_SWITCHER_SCHEMA`) appear on the match line or within a 5-line forward window. The `desktop.` anchor requires a quote prefix to avoid matching non-schema contexts like `desktop.png` or `this.desktop.theme`. Also skipped in `service/` directories.
+- **Guard**: Suppressed when `schema.*org.gnome.` (excluding `shell.extensions.`), string-literal-anchored system schema substrings (`'desktop.` or `"desktop.`), bare `shell.app-switcher`, or enumerated system-schema constants (`KEYBINDINGS_SCHEMA`, `NOTIFICATIONS_SCHEMA`, `DESKTOP_SCHEMA`, `INTERFACE_SCHEMA`, `WM_SCHEMA`, `MUTTER_SCHEMA`, `APP_SWITCHER_SCHEMA`) appear on the match line or within a 5-line forward window. The `desktop.` anchor requires a quote prefix to avoid matching property-access contexts like `this.desktop.theme`. Also skipped in `service/` directories.
 
 ### R-SLOP-25: Main.extensionManager.enable/disable
 - **Severity**: advisory

tests/assertions/dash-to-panel-fixes.sh

@@ -54,5 +54,6 @@ echo ""
 # --- system-schema-bare (R-SLOP-24 guard for bare system schema identifiers) ---
 echo "=== system-schema-bare ==="
 run_lint "system-schema-bare@test"
-assert_output_not_contains "R-SLOP-24 suppressed for bare desktop. schema" "\[WARN\].*R-SLOP-24"
+assert_exit_code "exits with 0 (system schema guards suppress R-SLOP-24)" 0
+assert_output_not_contains "R-SLOP-24 suppressed for bare system schema identifiers" "\[WARN\].*R-SLOP-24"
 echo ""