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

gui_2.py

@@ -260,6 +260,7 @@ class App:
   self.active_track: Track | None = None
   self.active_tickets: list[dict[str, Any]] = []
   self.active_tier: str | None = None
+  self.ui_focus_agent: str | None = None
   self.mma_status = "idle"
   self._pending_mma_approval: dict[str, Any] | None = None
   self._mma_approval_open = False
@@ -1746,6 +1747,21 @@ class App:
    if self.show_windows.get("Operations Hub", False):
     exp, self.show_windows["Operations Hub"] = imgui.begin("Operations Hub", self.show_windows["Operations Hub"])
     if exp:
+     imgui.text("Focus Agent:")
+     imgui.same_line()
+     focus_label = self.ui_focus_agent or "All"
+     if imgui.begin_combo("##focus_agent", focus_label, imgui.ComboFlags_.width_fit_preview):
+      if imgui.selectable("All", self.ui_focus_agent is None)[0]:
+       self.ui_focus_agent = None
+      for tier in ["Tier 2", "Tier 3", "Tier 4"]:
+       if imgui.selectable(tier, self.ui_focus_agent == tier)[0]:
+        self.ui_focus_agent = tier
+      imgui.end_combo()
+     imgui.same_line()
+     if self.ui_focus_agent:
+      if imgui.button("x##clear_focus"):
+       self.ui_focus_agent = None
+     imgui.separator()
      if imgui.begin_tab_bar("OperationsTabs"):
       if imgui.begin_tab_item("Tool Calls")[0]:
        self._render_tool_calls_panel()
@@ -2968,14 +2984,17 @@ class App:
   imgui.separator()
   imgui.begin_child("scroll_area")
   clipper = imgui.ListClipper()
-  clipper.begin(len(self._tool_log))
+  tool_log_filtered = self._tool_log if not self.ui_focus_agent else [
+   e for e in self._tool_log if e.get("source_tier") == self.ui_focus_agent
+  ]
+  clipper = imgui.ListClipper()
+  clipper.begin(len(tool_log_filtered))
   while clipper.step():
    for i_minus_one in range(clipper.display_start, clipper.display_end):
-    entry = self._tool_log[i_minus_one]
+    i = i_minus_one + 1
+    entry = tool_log_filtered[i_minus_one]
     script = entry["script"]
     result = entry["result"]
-    script, result, _ = self._tool_log[i_minus_one]
-    first_line = script.strip().splitlines()[0][:80] if script.strip() else "(empty)"
     imgui.text_colored(C_KEY, f"Call #{i}: {first_line}")
     # Script Display
     imgui.text_colored(C_LBL, "Script:")
@@ -3411,6 +3430,8 @@ class App:
    imgui.push_style_color(imgui.Col_.child_bg, vec4(40, 30, 20))
   imgui.begin_child("comms_scroll", imgui.ImVec2(0, 0), False, imgui.WindowFlags_.horizontal_scrollbar)
   log_to_render = self.prior_session_entries if self.is_viewing_prior_session else list(self._comms_log)
+  if self.ui_focus_agent and not self.is_viewing_prior_session:
+   log_to_render = [e for e in log_to_render if e.get("source_tier") == self.ui_focus_agent]
   for idx_minus_one, entry in enumerate(log_to_render):
    idx = idx_minus_one + 1
    local_ts = entry.get("local_ts", 0)
@@ -3442,6 +3463,9 @@ class App:
    imgui.text_colored(KIND_COLORS.get(k, C_VAL), k)
    imgui.same_line()
    imgui.text_colored(C_LBL, f"{entry.get('provider', '?')}/{entry.get('model', '?')}")
+   imgui.same_line()
+   tier_label = entry.get("source_tier") or "main"
+   imgui.text_colored(C_SUB, f"[{tier_label}]")
    payload = entry.get("payload", {})
    if k == "request":
     self._render_heavy_text("message", payload.get("message", ""))