phase: 178_split_thinking_levels

## Phase 178 — final verification pass: 100% green

**Verified (all 5 tasks complete in `complete/178_split_thinking_levels/`):**
- `config.py` rename (`llm_chat_thinking_level` default `low`) + new `llm_summary_thinking_level` (default `""`); two `CATALOG` rows; `.env.example` replaced; no stale old-key references (only intentional negative pins in tests)
- Wire split: `chat_stream()` → chat level, one-shot `chat()` → summary level (absent `extra_body` when empty); per-turn line reads chat level only

**Gates:**
- `uv run pytest -k "config and thinking" -v` → 7 passed (defaults + env overrides both knobs)
- `uv run pytest` (unit + integration) → 4170 tests, exit 0; `--cov=app` → **99%** (>90% ✓)
- `uv run ruff check .` clean; `uv run pyright` clean
- `uv run pytest tests/e2e/test_split_thinking_levels.py -v --no-cov` → 3 passed in isolation
- `test_admin_settings_panel.py` + `test_admin_settings_layout.py` → 17 passed in isolation

**Completion criteria:** all 6 test/doc criteria ✅ (admin GET lists both keys, old key gone — integration + E2E pins); commit + phase-dir move = harness's job.

**Documentation:** README.md — both new env vars correctly documented in the LLM (aipi) table with defaults/wire-mapping/off-rule, defaults match `config.py`, all `.env.example` vars covered: verified consistent, no changes needed. AGENTS.md — all referenced files/commands verified to exist, no phase-178 impact (no UI code change, A4): verified consistent, no changes needed.

**Decisions:** none required — no live changes made (E2E booted its own app subprocess against the existing DB).

**Next pending phase:** none — 178 is the last phase in `todo/`.

tests/unit/test_config.py

@@ -105,32 +105,65 @@ def test_llm_summary_model_env_override(monkeypatch) -> None:
     assert s.llm_summary_model == "mini"
 
 
-def test_llm_thinking_level_default_is_low(monkeypatch: pytest.MonkeyPatch) -> None:
-    """Phase 172: the model's thinking level defaults to ``low``
-    (``BOR_LLM_THINKING_LEVEL`` unset)."""
-    monkeypatch.delenv("BOR_LLM_THINKING_LEVEL", raising=False)
-    s = _settings()
-    assert s.llm_thinking_level == "low"
-
-
-def test_llm_thinking_level_env_override(monkeypatch) -> None:
-    """Phase 172 (A4): free-form like ``llm_chat_model`` —
-    ``BOR_LLM_THINKING_LEVEL=high`` resolves to ``"high"`` (no
-    allowlist, no validator)."""
-    monkeypatch.setenv("BOR_LLM_THINKING_LEVEL", "high")
-    s = _settings()
-    assert s.llm_thinking_level == "high"
-
-
-def test_llm_thinking_level_empty_env_value_stays_empty(
+def test_llm_chat_thinking_level_default_is_low(
     monkeypatch: pytest.MonkeyPatch,
 ) -> None:
-    """Phase 172 (A2): the EMPTY value is the off switch — it must not
-    be coerced back to the default (trimming happens only at the wire,
-    task 03; no normalization at load)."""
-    monkeypatch.setenv("BOR_LLM_THINKING_LEVEL", "")
+    """Phase 178 (the phase-172 knob, renamed): the chat turn's
+    thinking level defaults to ``low`` (``BOR_LLM_CHAT_THINKING_LEVEL``
+    unset)."""
+    monkeypatch.delenv("BOR_LLM_CHAT_THINKING_LEVEL", raising=False)
     s = _settings()
-    assert s.llm_thinking_level == ""
+    assert s.llm_chat_thinking_level == "low"
+
+
+def test_llm_chat_thinking_level_env_override(monkeypatch) -> None:
+    """Phase 178 (A4, kept): free-form like ``llm_chat_model`` —
+    ``BOR_LLM_CHAT_THINKING_LEVEL=high`` resolves to ``"high"`` (no
+    allowlist, no validator)."""
+    monkeypatch.setenv("BOR_LLM_CHAT_THINKING_LEVEL", "high")
+    s = _settings()
+    assert s.llm_chat_thinking_level == "high"
+
+
+def test_llm_chat_thinking_level_empty_env_value_stays_empty(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """Phase 178 (A2, kept): the EMPTY value is the off switch — it
+    must not be coerced back to the default (trimming happens only at
+    the wire; no normalization at load)."""
+    monkeypatch.setenv("BOR_LLM_CHAT_THINKING_LEVEL", "")
+    s = _settings()
+    assert s.llm_chat_thinking_level == ""
+
+
+def test_llm_summary_thinking_level_default_is_empty(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """Phase 178 (A2): the one-shot summary thinking level defaults to
+    EMPTY (``BOR_LLM_SUMMARY_THINKING_LEVEL`` unset) — the TODO's
+    "none" means absence, never a literal "none" string."""
+    monkeypatch.delenv("BOR_LLM_SUMMARY_THINKING_LEVEL", raising=False)
+    s = _settings()
+    assert s.llm_summary_thinking_level == ""
+
+
+def test_llm_summary_thinking_level_env_override(monkeypatch) -> None:
+    """Phase 178: free-form like the chat level —
+    ``BOR_LLM_SUMMARY_THINKING_LEVEL=high`` resolves to ``"high"``
+    (no allowlist, no validator)."""
+    monkeypatch.setenv("BOR_LLM_SUMMARY_THINKING_LEVEL", "high")
+    s = _settings()
+    assert s.llm_summary_thinking_level == "high"
+
+
+def test_llm_summary_thinking_level_empty_env_value_stays_empty(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    """Phase 178 (A2, kept): the EMPTY value is the off switch — it
+    must not be coerced to anything at load (no normalization)."""
+    monkeypatch.setenv("BOR_LLM_SUMMARY_THINKING_LEVEL", "")
+    s = _settings()
+    assert s.llm_summary_thinking_level == ""
 
 
 def test_summary_max_chars_default_and_env_override(monkeypatch: pytest.MonkeyPatch) -> None: