feat(mma): Phase 3 — Focus Agent UI + filter logic

- gui_2.__init__: add ui_focus_agent: str | None = None
- _gui_func: Focus Agent combo (All/Tier2/3/4) + clear button above OperationsTabs
- _render_comms_history_panel: filter by ui_focus_agent; show [source_tier] label per entry
- _render_tool_calls_panel: pre-filter with tool_log_filtered; fix missing i=i_minus_one+1; remove stale tuple destructure
- tests: 6 new Phase 3 tests, 18/18 total

tests/test_mma_agent_focus_phase3.py

@@ -0,0 +1,109 @@
+"""
+Tests for mma_agent_focus_ux_20260302 — Phase 3: Focus Agent UI + Filter Logic.
+"""
+from typing import Generator
+import pytest
+from unittest.mock import patch
+from gui_2 import App
+
+
+@pytest.fixture
+def app_instance() -> Generator[App, None, None]:
+ with (
+  patch('gui_2.load_config', return_value={'gui': {'show_windows': {}}}),
+  patch('gui_2.save_config'),
+  patch('gui_2.project_manager'),
+  patch('gui_2.session_logger'),
+  patch('gui_2.immapp.run'),
+  patch.object(App, '_load_active_project'),
+  patch.object(App, '_fetch_models'),
+  patch.object(App, '_load_fonts'),
+  patch.object(App, '_post_init')
+ ):
+  yield App()
+
+
+def test_ui_focus_agent_state_var_exists(app_instance):
+ """App.__init__ must expose ui_focus_agent: str | None = None."""
+ assert hasattr(app_instance, 'ui_focus_agent'), "ui_focus_agent missing from App"
+ assert app_instance.ui_focus_agent is None
+
+
+def test_tool_log_filter_all(app_instance):
+ """When ui_focus_agent is None, all tool log entries are visible."""
+ app = app_instance
+ app._tool_log = [
+  {"script": "a", "result": "r1", "ts": 1.0, "source_tier": "Tier 2"},
+  {"script": "b", "result": "r2", "ts": 2.0, "source_tier": "Tier 3"},
+  {"script": "c", "result": "r3", "ts": 3.0, "source_tier": None},
+ ]
+ app.ui_focus_agent = None
+ filtered = app._tool_log if not app.ui_focus_agent else [
+  e for e in app._tool_log if e.get("source_tier") == app.ui_focus_agent
+ ]
+ assert len(filtered) == 3
+
+
+def test_tool_log_filter_tier3_only(app_instance):
+ """When ui_focus_agent='Tier 3', only Tier 3 entries are shown."""
+ app = app_instance
+ app._tool_log = [
+  {"script": "a", "result": "r1", "ts": 1.0, "source_tier": "Tier 2"},
+  {"script": "b", "result": "r2", "ts": 2.0, "source_tier": "Tier 3"},
+  {"script": "c", "result": "r3", "ts": 3.0, "source_tier": "Tier 3"},
+  {"script": "d", "result": "r4", "ts": 4.0, "source_tier": None},
+ ]
+ app.ui_focus_agent = "Tier 3"
+ filtered = [e for e in app._tool_log if e.get("source_tier") == app.ui_focus_agent]
+ assert len(filtered) == 2
+ assert all(e["source_tier"] == "Tier 3" for e in filtered)
+
+
+def test_tool_log_filter_excludes_none_tier(app_instance):
+ """Filtering to Tier 2 excludes entries with source_tier=None."""
+ app = app_instance
+ app._tool_log = [
+  {"script": "a", "result": "r1", "ts": 1.0, "source_tier": "Tier 2"},
+  {"script": "b", "result": "r2", "ts": 2.0, "source_tier": None},
+ ]
+ app.ui_focus_agent = "Tier 2"
+ filtered = [e for e in app._tool_log if e.get("source_tier") == app.ui_focus_agent]
+ assert len(filtered) == 1
+ assert filtered[0]["script"] == "a"
+
+
+def test_comms_log_filter_tier3_only(app_instance):
+ """When ui_focus_agent='Tier 3', comms filter excludes other tiers."""
+ app = app_instance
+ import time
+ app._comms_log = [
+  {"ts": "10:00", "direction": "OUT", "kind": "request", "provider": "gemini",
+   "model": "m", "payload": {}, "source_tier": "Tier 2", "local_ts": time.time()},
+  {"ts": "10:01", "direction": "IN", "kind": "response", "provider": "gemini",
+   "model": "m", "payload": {}, "source_tier": "Tier 3", "local_ts": time.time()},
+  {"ts": "10:02", "direction": "OUT", "kind": "request", "provider": "gemini",
+   "model": "m", "payload": {}, "source_tier": None, "local_ts": time.time()},
+ ]
+ app.ui_focus_agent = "Tier 3"
+ app.is_viewing_prior_session = False
+ log_to_render = list(app._comms_log)
+ if app.ui_focus_agent and not app.is_viewing_prior_session:
+  log_to_render = [e for e in log_to_render if e.get("source_tier") == app.ui_focus_agent]
+ assert len(log_to_render) == 1
+ assert log_to_render[0]["source_tier"] == "Tier 3"
+
+
+def test_comms_log_filter_not_applied_for_prior_session(app_instance):
+ """Focus filter must NOT apply when viewing prior session log."""
+ app = app_instance
+ app.ui_focus_agent = "Tier 3"
+ app.is_viewing_prior_session = True
+ prior = [
+  {"ts": "10:00", "source_tier": "Tier 2"},
+  {"ts": "10:01", "source_tier": "Tier 3"},
+ ]
+ app.prior_session_entries = prior
+ log_to_render = app.prior_session_entries if app.is_viewing_prior_session else list(app._comms_log)
+ if app.ui_focus_agent and not app.is_viewing_prior_session:
+  log_to_render = [e for e in log_to_render if e.get("source_tier") == app.ui_focus_agent]
+ assert len(log_to_render) == 2