fix(display): a raising display() counts as a circuit-breaker failure (#707)

The first-frame dispatch (_dispatch_first_frame) now asks PluginExecutor.execute_display() to re-raise (raise_errors=True) and records a raise inside the executor as a breaker failure, with the original exception as last_error, instead of a success. The screen is still an empty pass and rotation is unchanged; a hung display() is still recorded once, as a hang. The run-loop golden trace plugin_error.json is regenerated (crashy now records health failures and is skipped by the breaker), and behaviour 7 is dropped from docs/RUN_LOOP_REDESIGN.md.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

test/test_run_loop_golden.py

@@ -61,8 +61,9 @@ def scenario_all_empty(h: RunLoopHarness):
 def scenario_plugin_error(h: RunLoopHarness):
     # broken's dispatch raises (no display lock: loading failed part-way),
     # so all its modes are skipped together; two failures open the breaker.
-    # crashy's display() raises inside the executor, which reports False:
-    # an empty pass ("raised"), not a failure, so its modes are not skipped.
+    # crashy's display() raises inside the executor: an empty pass
+    # ("raised") that also counts as a breaker failure, so after two raises
+    # it is skipped by the breaker. Its modes are not skipped together.
     h.add_plugin(FakePlugin("clock", ["clock"], duration=10))
     h.add_plugin(FakePlugin("broken", ["broken_a", "broken_b"], duration=10), lock=False)
     h.add_plugin(FakePlugin("weather", ["weather"], duration=10))