feat(tui): persona surface — sticky header + TabPane (v0.13.0)

Step 3 of the Worldtree #204 integration: visible persona-state UX.
Pairs with v0.11.0's AffectUpdate SSE event + v0.12.0's
get_persona_state HTTP client — together those gave the data; this
bump surfaces it.

Two surfaces (Option C: both):

Sticky persona-header (top of screen, dock=top, height=1):
- Shape: `agent_id · dominant_emotion · pad(P, A, D) · N emotions
  active` — concise enough for at-a-glance scan above the chat
- Starts hidden via `.empty` CSS class; height collapses to 0 when
  the agent has no persona surface
- Refreshes on AffectUpdate(status="current") snapshots

Persona TabPane (Ctrl+4):
- Full snapshot detail: dominant emotion, PAD axes with baseline +
  delta, mood drift, active emotions with intensity + decay
  (minutes-rounded), last_updated_at footer
- Replaced (not appended) on each new snapshot — snapshots are
  absolute state, not incremental

Lifecycle:
- on_mount spawns a Textual worker that calls get_persona_state to
  hydrate header + pane before turn 1
- PersonaNotConfigured (domari, muninn, Tier 3) → pane carries an
  italic placeholder, header stays empty
- AgentNotAvailable / AuthScopeDenied / network error → italic
  failure placeholder; audit-logged; never crashes
- Presenter's render() takes an optional `on_persona_snapshot`
  callback so AffectUpdate(current) refreshes both surfaces during
  a live turn (no widget coupling — App owns the callback)

Tests: 10 new (4 formatters, 3 presenter callback, 4 layout/binding/
hydration). Full suite: 313 passing.

tests/test_tui.py

@@ -934,6 +934,156 @@ class TestCancelViaSse:
         assert audit_lines[1].startswith("cancel_post failed turn_id=42 CancelFailed")
 
 
+class TestPersonaFormatters:
+    """v0.13.0 — _format_persona_header / _format_persona_detail rendering."""
+
+    def test_header_compact_summary(self) -> None:
+        """header_compact_summary: agent_id · dominant_emotion · pad(P,A,D) · N emotions."""
+        from ratatoskr.tui import _format_persona_header
+
+        snapshot = {
+            "agent_id": "mimir",
+            "dominant_emotion": "curiosity",
+            "pad": {"pleasure": 0.52, "arousal": 0.47, "dominance": 0.50},
+            "emotions_active": [
+                {"type": "curiosity"}, {"type": "joy"},
+            ],
+        }
+        line = _format_persona_header(snapshot)
+        assert "mimir" in line
+        assert "curiosity" in line
+        assert "pad(0.52, 0.47, 0.5)" in line
+        assert "2 emotions active" in line
+
+    def test_header_singular_emotion(self) -> None:
+        """header_singular_emotion: single emotion → '1 emotion active' (no 's')."""
+        from ratatoskr.tui import _format_persona_header
+
+        line = _format_persona_header(
+            {
+                "agent_id": "mimir",
+                "dominant_emotion": "calm",
+                "pad": {"pleasure": 0.5, "arousal": 0.4, "dominance": 0.5},
+                "emotions_active": [{"type": "calm"}],
+            }
+        )
+        assert "1 emotion active" in line
+        assert "1 emotions" not in line
+
+    def test_header_no_emotions_drops_count(self) -> None:
+        """header_no_emotions_drops_count: empty emotions list → no count suffix."""
+        from ratatoskr.tui import _format_persona_header
+
+        line = _format_persona_header(
+            {
+                "agent_id": "mimir",
+                "dominant_emotion": "?",
+                "pad": {"pleasure": 0.5, "arousal": 0.4, "dominance": 0.5},
+                "emotions_active": [],
+            }
+        )
+        assert "emotion" not in line  # neither "1 emotion" nor "N emotions"
+
+    def test_detail_renders_full_snapshot(self) -> None:
+        """detail_renders_full_snapshot: PAD axes + baseline + delta + drift +
+        emotions + last_updated_at all surface in the multi-line render.
+        """
+        from ratatoskr.tui import _format_persona_detail
+
+        snapshot = {
+            "agent_id": "mimir",
+            "pad": {"pleasure": 0.52, "arousal": 0.47, "dominance": 0.50},
+            "dominant_emotion": "curiosity",
+            "emotions_active": [
+                {"type": "curiosity", "intensity": 0.6, "decay_remaining_s": 202.7}
+            ],
+            "baseline_pad": {"pleasure": 0.50, "arousal": 0.40, "dominance": 0.50},
+            "mood_drift": {"valence_delta": 0.02, "arousal_delta": 0.07},
+            "last_updated_at": "2026-05-25T22:30:18+00:00",
+        }
+        detail = _format_persona_detail(snapshot)
+        assert "Persona snapshot · mimir" in detail
+        assert "Dominant emotion: curiosity" in detail
+        assert "pleasure" in detail
+        assert "baseline 0.5" in detail
+        assert "+0.02" in detail or "0.02" in detail
+        assert "valence_delta" in detail
+        assert "curiosity" in detail
+        assert "intensity 0.6" in detail
+        assert "decay 3.4m" in detail
+        assert "2026-05-25T22:30:18+00:00" in detail
+
+
+class TestPresenterPersonaCallback:
+    """v0.13.0 — presenter wires AffectUpdate snapshots into a callback."""
+
+    def test_current_invokes_callback_with_snapshot(self) -> None:
+        """current_invokes_callback_with_snapshot: AffectUpdate(current, snapshot)
+        calls on_persona_snapshot(snapshot)."""
+        from ratatoskr.sse_client import AffectUpdate
+        from ratatoskr.tui import TuiPresenterState
+
+        captured: list = []
+        state = TuiPresenterState()
+        snapshot = {"agent_id": "mimir", "pad": {"pleasure": 0.5}}
+        state.render(
+            AffectUpdate(sse_id=SID, status="current", turn_id=42, snapshot=snapshot),
+            transcript=MagicMock(),
+            tools_log=MagicMock(),
+            debug_log=MagicMock(),
+            thinking_log=MagicMock(),
+            raw=False,
+            on_persona_snapshot=captured.append,
+        )
+        assert captured == [snapshot]
+
+    def test_scheduled_does_not_invoke_callback(self) -> None:
+        """scheduled_does_not_invoke_callback: status=scheduled has no snapshot,
+        so the callback is skipped (would be called with None otherwise)."""
+        from ratatoskr.sse_client import AffectUpdate
+        from ratatoskr.tui import TuiPresenterState
+
+        captured: list = []
+        state = TuiPresenterState()
+        state.render(
+            AffectUpdate(sse_id=SID, status="scheduled", turn_id=42, snapshot=None),
+            transcript=MagicMock(),
+            tools_log=MagicMock(),
+            debug_log=MagicMock(),
+            thinking_log=MagicMock(),
+            raw=False,
+            on_persona_snapshot=captured.append,
+        )
+        assert captured == []
+
+    def test_callback_exception_swallowed(self) -> None:
+        """callback_exception_swallowed: a raising callback does NOT crash the
+        presenter — the audit line still landed (it precedes the callback).
+        """
+        from ratatoskr.sse_client import AffectUpdate
+        from ratatoskr.tui import TuiPresenterState
+
+        def boom(_snap: dict) -> None:
+            raise RuntimeError("widget tearing down")
+
+        debug_log = MagicMock()
+        state = TuiPresenterState()
+        # Should NOT raise
+        state.render(
+            AffectUpdate(
+                sse_id=SID, status="current", turn_id=42, snapshot={"agent_id": "x"}
+            ),
+            transcript=MagicMock(),
+            tools_log=MagicMock(),
+            debug_log=debug_log,
+            thinking_log=MagicMock(),
+            raw=False,
+            on_persona_snapshot=boom,
+        )
+        # Audit line still emitted (it runs before the callback)
+        assert debug_log.write.called
+
+
 class TestAppMount:
     """on_mount narrows per issue #6: only identity-widget population.
 
@@ -1104,6 +1254,43 @@ class TestLayoutShape:
             await pilot.pause()
             assert app.query_one("#side-panes", TabbedContent).active == "debug-tab"
 
+    async def test_persona_tab_exists(self) -> None:
+        """persona_tab_exists [v0.13.0]: right column has Persona TabPane +
+        #persona-log RichLog as descendant.
+        """
+        from textual.widgets import RichLog, TabPane
+
+        app = _resolved_app(_args_new(), session_id="s-new12345", agent_id="mimir")
+        async with app.run_test() as pilot:
+            await pilot.pause()
+            persona_tab = app.query_one("#persona-tab", TabPane)
+            persona_log = app.query_one("#persona-log", RichLog)
+            assert persona_log in persona_tab.walk_children()
+
+    async def test_ctrl_4_activates_persona_tab(self) -> None:
+        """ctrl_4_activates_persona_tab [v0.13.0]: Ctrl+4 → active == 'persona-tab'."""
+        from textual.widgets import TabbedContent
+
+        app = _resolved_app(_args_new(), session_id="s-new12345", agent_id="mimir")
+        async with app.run_test() as pilot:
+            await pilot.pause()
+            await pilot.press("ctrl+4")
+            await pilot.pause()
+            assert app.query_one("#side-panes", TabbedContent).active == "persona-tab"
+
+    async def test_persona_header_starts_empty(self) -> None:
+        """persona_header_starts_empty [v0.13.0]: sticky persona-header widget
+        exists, starts hidden (height collapsed via .empty class) until
+        hydration succeeds.
+        """
+        from textual.widgets import Static
+
+        app = _resolved_app(_args_new(), session_id="s-new12345", agent_id="mimir")
+        async with app.run_test() as pilot:
+            await pilot.pause()
+            header = app.query_one("#persona-header", Static)
+            assert "empty" in header.classes
+
     async def test_done_label_styled_success(self) -> None:
         """done_label_styled_success [v0.9.0]: [done] label mounts as Static
         carrying a RichText with Aurora green style. Inspect the mounted