feat(settings): CEO display name is configurable, Renzo hardcode removed (#612)

The header chip and the Settings User Info card rendered a literal 'Renzo'.
The name now lives in the system_settings store under ceo_name (validated:
trimmed, non-empty, max 60 chars) with the same client-served default the
transcript-retention card uses, editable inline from the User Info card.
Agent prompts already refer to 'the CEO' generically, so no prompt rewiring;
the two agent-facing RAG docs drop the name too. License/CLA copyright is
untouched.

Co-authored-by: Renn F <rennf93@users.noreply.github.com>

tests/unit/services/test_settings_service.py

@@ -25,6 +25,14 @@ def test_validate_retention_requires_positive_int() -> None:
         validate_setting("transcript_retention_days", "abc")
 
 
+def test_validate_ceo_name_requires_nonempty_bounded_string() -> None:
+    validate_setting("ceo_name", "Alice")  # ok, no raise
+    with pytest.raises(SettingValidationError):
+        validate_setting("ceo_name", "   ")
+    with pytest.raises(SettingValidationError):
+        validate_setting("ceo_name", "x" * 61)
+
+
 _DEFAULT_RETENTION = 14
 _NEW_RETENTION = 30
 
@@ -54,3 +62,18 @@ async def test_set_rejects_invalid_value(db_session: Any) -> None:
     svc = get_settings_service(db_session)
     with pytest.raises(SettingValidationError):
         await svc.set("transcript_retention_days", "-5")
+
+
+@pytest.mark.asyncio
+async def test_ceo_name_set_then_get_roundtrips(db_session: Any) -> None:
+    svc = get_settings_service(db_session)
+    assert await svc.get("ceo_name") is None  # unset, panel supplies fallback
+    await svc.set("ceo_name", "Alice")
+    assert await svc.get("ceo_name") == "Alice"
+
+
+@pytest.mark.asyncio
+async def test_ceo_name_set_rejects_blank_value(db_session: Any) -> None:
+    svc = get_settings_service(db_session)
+    with pytest.raises(SettingValidationError):
+        await svc.set("ceo_name", "   ")