refactor(webui): improve visual consistency (#5249)

nanobot/channels/websocket/tests/test_websocket_channel.py

@@ -2545,6 +2545,7 @@ async def test_settings_api_returns_safe_subset_and_updates_whitelist(
     )
     config.tools.web.search.provider = "brave"
     config.tools.web.search.api_key = "brave-secret"
+    expected_timezone = config.agents.defaults.timezone
     save_config(config, config_path)
     monkeypatch.setattr("nanobot.config.loader._current_config_path", config_path)
     monkeypatch.setattr(
@@ -2585,7 +2586,7 @@ async def test_settings_api_returns_safe_subset_and_updates_whitelist(
         assert body["agent"]["provider"] == "openai"
         assert body["agent"]["model_preset"] == "default"
         assert body["agent"]["max_tokens"] == 8192
-        assert body["agent"]["timezone"] == "UTC"
+        assert body["agent"]["timezone"] == expected_timezone
         assert "bot_name" not in body["agent"]
         assert "bot_icon" not in body["agent"]
         assert body["agent"]["tool_hint_max_length"] == 40

nanobot/config/schema.py

@@ -2,11 +2,12 @@
 from __future__ import annotations
 
 from pathlib import Path
-from typing import TYPE_CHECKING, Any, ClassVar, Literal
+from typing import TYPE_CHECKING, Any, ClassVar, Literal, cast
 
 from pydantic import AliasChoices, ConfigDict, Field, field_validator, model_validator
 from pydantic_settings import BaseSettings, SettingsConfigDict
 
+from nanobot.config.timezone import detect_system_timezone
 from nanobot.config_base import Base
 from nanobot.cron.types import CronSchedule
 
@@ -140,7 +141,8 @@ class AgentDefaults(Base):
         serialization_alias="toolHintMaxLength",
     )  # Max characters for tool hint display (e.g. "$ cd …/project && npm test")
     reasoning_effort: str | None = None  # low / medium / high / xhigh / max / adaptive / none — LLM thinking effort; None preserves the provider default
-    timezone: str = "UTC"  # IANA timezone, e.g. "Asia/Shanghai", "America/New_York"
+    timezone: str = "UTC"  # Effective IANA timezone, e.g. "Asia/Shanghai"
+    timezone_mode: Literal["auto", "manual"] = "auto"
     bot_name: str = "nanobot"  # Display name shown in CLI prompts (e.g. "{name} is thinking...")
     bot_icon: str = "🐈"  # Short icon (emoji or text) shown next to the bot name in CLI; "" to omit
     unified_session: bool = False  # Share one session across all channels (single-user multi-device)
@@ -164,6 +166,22 @@ class AgentDefaults(Base):
     )  # Consolidation target ratio (0.5 = 50% of budget retained after compression)
     dream: DreamConfig = Field(default_factory=DreamConfig)
 
+    @model_validator(mode="before")
+    @classmethod
+    def resolve_timezone(cls, value: object) -> object:
+        """Detect new defaults server-side while preserving configured timezones."""
+        if not isinstance(value, dict):
+            return value
+
+        data = dict(cast(dict[str, object], value))
+        timezone_mode = data.get("timezoneMode", data.get("timezone_mode"))
+        if timezone_mode is None:
+            timezone_mode = "manual" if "timezone" in data else "auto"
+            data["timezoneMode"] = timezone_mode
+        if timezone_mode == "auto":
+            data["timezone"] = detect_system_timezone()
+        return data
+
     @field_validator("timezone")
     @classmethod
     def validate_timezone(cls, value: str) -> str:

nanobot/config/timezone.py

@@ -0,0 +1,19 @@
+"""Backend timezone detection for automatic agent defaults."""
+
+from zoneinfo import ZoneInfo
+
+from tzlocal import get_localzone_name
+
+_UTC_ALIASES = frozenset(
+    {"Etc/GMT", "Etc/UTC", "GMT", "GMT0", "Greenwich", "UCT", "Universal", "Zulu"}
+)
+
+
+def detect_system_timezone() -> str:
+    """Return the host's IANA timezone, falling back safely to UTC."""
+    try:
+        timezone = get_localzone_name()
+        ZoneInfo(timezone)
+    except Exception:
+        return "UTC"
+    return "UTC" if timezone in _UTC_ALIASES else timezone

nanobot/webui/settings_api.py

@@ -1399,10 +1399,12 @@ def update_agent_settings(query: QueryParams) -> dict[str, Any]:
             ZoneInfo(timezone)
         except Exception:
             raise WebUISettingsError("invalid timezone") from None
-        if defaults.timezone != timezone:
+        timezone_changed = defaults.timezone != timezone
+        if timezone_changed or defaults.timezone_mode != "manual":
             defaults.timezone = timezone
+            defaults.timezone_mode = "manual"
             changed = True
-            restart_required = True
+            restart_required = timezone_changed
 
     tool_hint_max_length = _query_first_alias(
         query,