Add skip_prefilter option to control generator

Local LLM prefilter (llama3.2 3B) was incorrectly skipping annex chunks
that contain concrete requirements. Added skip_prefilter flag to bypass
the local pre-filter and send all chunks directly to Anthropic API.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend-compliance/compliance/api/control_generator_routes.py

@@ -54,6 +54,7 @@ class GenerateRequest(BaseModel):
     skip_web_search: bool = False
     dry_run: bool = False
     regulation_filter: Optional[List[str]] = None  # Only process these regulation_code prefixes
+    skip_prefilter: bool = False  # Skip local LLM pre-filter, send all chunks to API
 
 
 class GenerateResponse(BaseModel):
@@ -146,6 +147,7 @@ async def start_generation(req: GenerateRequest):
         skip_web_search=req.skip_web_search,
         dry_run=req.dry_run,
         regulation_filter=req.regulation_filter,
+        skip_prefilter=req.skip_prefilter,
     )
 
     if req.dry_run: