fix: update pydantic schemas to v2 syntax

- Replace Config class with ConfigDict
- Add cron expression validation
- Add missing updated_at to Schedule
- Add JobExecutionUpdate schema

backend/app/schemas.py

@@ -1,6 +1,7 @@
-from pydantic import BaseModel, Field
+from pydantic import BaseModel, Field, ConfigDict, field_validator
 from typing import Optional, List, Dict, Any
 from datetime import datetime
+import re
 
 # Source schemas
 class SourceBase(BaseModel):
@@ -20,8 +21,7 @@ class Source(SourceBase):
     created_at: datetime
     updated_at: datetime
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 # Job schemas
 class JobBase(BaseModel):
@@ -47,8 +47,7 @@ class Job(JobBase):
     created_at: datetime
     updated_at: datetime
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 # Schedule schemas
 class ScheduleBase(BaseModel):
@@ -56,6 +55,14 @@ class ScheduleBase(BaseModel):
     cron_expression: str
     enabled: bool = True
 
+    @field_validator('cron_expression')
+    @classmethod
+    def validate_cron(cls, v: str) -> str:
+        pattern = r'^([0-9*,/-]+)\s+([0-9*,/-]+)\s+([0-9*,/-]+)\s+([0-9*,/-]+)\s+([0-9*,/-]+)$'
+        if not re.match(pattern, v):
+            raise ValueError('Invalid cron expression format')
+        return v
+
 class ScheduleCreate(ScheduleBase):
     pass
 
@@ -66,9 +73,9 @@ class ScheduleUpdate(BaseModel):
 class Schedule(ScheduleBase):
     id: int
     created_at: datetime
+    updated_at: datetime
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 # Execution schemas
 class JobExecutionBase(BaseModel):
@@ -87,8 +94,11 @@ class JobExecution(JobExecutionBase):
     bytes_backed_up: int = 0
     error_message: Optional[str] = None
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
+
+class JobExecutionUpdate(BaseModel):
+    status: Optional[str] = Field(None, pattern="^(pending|running|success|failed|cancelled)$")
+    error_message: Optional[str] = None
 
 # Backup schemas
 class BackupBase(BaseModel):
@@ -106,8 +116,7 @@ class Backup(BackupBase):
     id: int
     created_at: datetime
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 # Settings schemas
 class SettingBase(BaseModel):
@@ -123,8 +132,7 @@ class SettingUpdate(BaseModel):
 class Setting(SettingBase):
     updated_at: datetime
     
-    class Config:
-        from_attributes = True
+    model_config = ConfigDict(from_attributes=True)
 
 # Dashboard schemas
 class DashboardStats(BaseModel):