feat: file upload + expense report creation from Discuss attachments

- Discuss bot now reads ir.attachment from incoming messages; file-only
  messages no longer silently dropped
- ZIP files are described (contents listed) and bot asks clarifying
  question before acting; user's follow-up reply looks back for pending
  attachments so files don't need to be re-uploaded
- receipt_parser: extracts text from ZIP (recursive), JPG/PNG/etc (OCR),
  PDF (pdfplumber), HTML, TXT
- expenses_agent: full rewrite fixing broken method signatures; adds
  create_expense_sheet / create_expense / attach_receipt flow driven by
  LLM receipt parsing (Ollama, HIPAA-locked)
- master_agent: extra_context threads receipts + user_id into directives
- FastAPI /upload multipart endpoint; registered in main.py
- Odoo /ai/upload controller proxies files to agent service
- ab_ai_bot: dispatch_message_with_files() for multipart uploads

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

agent_service/main.py

@@ -10,7 +10,7 @@ from fastapi.middleware.cors import CORSMiddleware
 
 from .config import get_settings
 from . import app_state
-from .routers import dispatch, approval, registry, sweep, health
+from .routers import dispatch, approval, registry, sweep, health, upload
 
 logger = logging.getLogger(__name__)
 
@@ -224,6 +224,7 @@ def create_app() -> FastAPI:
         allow_headers=['*'],
     )
     app.include_router(dispatch.router)
+    app.include_router(upload.router)
     app.include_router(approval.router)
     app.include_router(registry.router)
     app.include_router(sweep.router)