fix: resolve 10 code review issues

High priority:
- Fix concurrent race condition for view_count/like_count (atomic update)
- Add route request ID tracking to prevent race conditions
- Filter get_joke by status=approved (no pending content leak)
- Add error feedback for like button

Performance:
- Optimize random joke query (avoid full table sort)
- Limit page_size max to 100 (DoS prevention)

Medium:
- Add localStorage quota error handling
- Handle empty AI response gracefully
- Fix generate content title extraction

Low:
- Add rejected_jokes to stats API
- Update dashboard to show rejected count

api/app/schemas/setting.py

@@ -0,0 +1,17 @@
+from pydantic import BaseModel, ConfigDict, Field
+
+
+class AiSettingBase(BaseModel):
+    provider: str = Field(default="nvidia")
+    api_base: str = Field(default="https://integrate.api.nvidia.com/v1")
+    api_key: str = Field(default="")
+    model_name: str = Field(default="nvidia/llama-3.1-nemotron-70b-instruct")
+    temperature: float = Field(default=0.7, ge=0, le=2)
+    max_tokens: int = Field(default=2048, ge=1)
+    crawl_enabled: bool = Field(default=False)
+    crawl_keywords: str = Field(default="")
+    max_pages_per_run: int = Field(default=3, ge=1)
+
+
+class AiSettingCreate(AiSettingBase):
+    pass