TIER-2 READ conductor/code_styleguides/error_handling.md end-to-end before Phase 5: refactor(gui_2): migrate L7208 render_beads_tab list to Result[T] (Phase 5)

Extract _render_beads_tab_list_result helper from the beads_client.BeadsClient
+ list_beads() try/except in render_beads_tab. Legacy wrapper drains errors
to app._last_request_errors per FR-BC-4 event-handler pattern.

[pre-audit] L7208 INTERNAL_BROAD_CATCH
[post-audit] V count: 4 -> 3 (L7208 removed)

tests/test_gui_2_result.py

@@ -1226,3 +1226,47 @@ def test_phase_5_l5920_render_external_editor_panel_config_result_failure():
  err = result.errors[0]
  assert err.source == "gui_2._render_external_editor_panel_config_result"
  assert "ext editor config blew up" in err.message
+
+
+def test_phase_5_l7208_render_beads_tab_list_result_success():
+ """
+ L7208 _render_beads_tab_list_result returns Result.ok=True on success.
+
+ The helper wraps the beads_client.BeadsClient(...) + list_beads() try/except in
+ render_beads_tab. On success, returns Result(data=beads) where beads is the
+ list of beads returned by list_beads().
+ """
+ from src import gui_2
+ from unittest.mock import MagicMock, patch
+ app = MagicMock()
+ app.active_project_root = "/proj/foo"
+ mock_client = MagicMock()
+ mock_bead   = MagicMock()
+ mock_bead.id     = "bd-1"
+ mock_bead.status = "todo"
+ mock_bead.title  = "test"
+ mock_client.list_beads.return_value = [mock_bead]
+ with patch("src.beads_client.BeadsClient", return_value=mock_client):
+  result = gui_2._render_beads_tab_list_result(app)
+ assert result.ok, f"Expected ok=True on success, got errors: {result.errors}"
+ assert result.data == [mock_bead]
+
+
+def test_phase_5_l7208_render_beads_tab_list_result_failure():
+ """
+ L7208 _render_beads_tab_list_result returns Result.ok=False with ErrorInfo on failure.
+
+ When BeadsClient construction or list_beads() raises, the helper converts
+ the exception to ErrorInfo and returns Result(data=[], errors=[ErrorInfo]).
+ """
+ from src import gui_2
+ from unittest.mock import MagicMock, patch
+ app = MagicMock()
+ app.active_project_root = "/proj/foo"
+ with patch("src.beads_client.BeadsClient", side_effect=RuntimeError("dolt backend down")):
+  result = gui_2._render_beads_tab_list_result(app)
+ assert not result.ok, f"Expected ok=False on failure, got data: {result.data}"
+ assert result.errors, "Expected at least one error on failure"
+ err = result.errors[0]
+ assert err.source == "gui_2._render_beads_tab_list_result"
+ assert "dolt backend down" in err.message