feat: 添加日历批量操作与客户端时区感知功能，优化前端 UI 交互体验

backend/src/schemas/agent/forwarded_props.py

@@ -0,0 +1,78 @@
+from __future__ import annotations
+
+from datetime import datetime
+import re
+from typing import Any
+from zoneinfo import ZoneInfo, ZoneInfoNotFoundError
+
+from pydantic import (
+    BaseModel,
+    ConfigDict,
+    Field,
+    StrictInt,
+    ValidationError,
+    field_validator,
+)
+
+_RFC3339_WITH_TZ_PATTERN = re.compile(
+    r"^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}(?:\.\d+)?(?:Z|[+-]\d{2}:\d{2})$"
+)
+
+
+class ClientTimeContext(BaseModel):
+    model_config = ConfigDict(extra="forbid")
+
+    device_timezone: str = Field(
+        ...,
+        description="IANA timezone from client device, e.g. America/Los_Angeles.",
+    )
+    client_now_iso: str = Field(
+        ...,
+        description="RFC3339 datetime with timezone offset from client device.",
+    )
+    client_epoch_ms: StrictInt = Field(
+        ...,
+        ge=0,
+        description="Unix epoch milliseconds from client device.",
+    )
+
+    @field_validator("device_timezone")
+    @classmethod
+    def validate_device_timezone(cls, value: str) -> str:
+        try:
+            ZoneInfo(value)
+        except ZoneInfoNotFoundError as exc:
+            raise ValueError("invalid client_time.device_timezone") from exc
+        return value
+
+    @field_validator("client_now_iso")
+    @classmethod
+    def validate_client_now_iso(cls, value: str) -> str:
+        if not _RFC3339_WITH_TZ_PATTERN.fullmatch(value):
+            raise ValueError("invalid client_time.client_now_iso")
+        normalized = value.replace("Z", "+00:00")
+        try:
+            parsed = datetime.fromisoformat(normalized)
+        except ValueError as exc:
+            raise ValueError("invalid client_time.client_now_iso") from exc
+        if parsed.tzinfo is None:
+            raise ValueError("invalid client_time.client_now_iso")
+        return value
+
+
+class ForwardedPropsPayload(BaseModel):
+    model_config = ConfigDict(extra="forbid")
+
+    client_time: ClientTimeContext | None = None
+
+
+def parse_forwarded_props_client_time(
+    forwarded_props: Any,
+) -> ClientTimeContext | None:
+    if not isinstance(forwarded_props, dict):
+        return None
+    try:
+        payload = ForwardedPropsPayload.model_validate(forwarded_props)
+    except ValidationError as exc:
+        raise ValueError("invalid RunAgentInput.forwardedProps") from exc
+    return payload.client_time