feat: add Workflow Engine and CRM module

[iPythoning]

Summary

Adds two major features to Clawith:

Multi-Agent Workflow Engine

• LLM-driven planning: Decomposes user business goals into executable agent steps
• Sequential execution with built-in retry for failed steps
• Rich deliverable viewer: Markdown rendering, table export (CSV), PDF export, CRM import
• Real-time polling UI with step-by-step progress tracking
• Contextual AI chat: Ask questions about workflow results in context

Lightweight CRM

• Drag-and-drop Kanban pipeline: Lead → Contacted → Qualified → Proposal → Negotiation → Won/Lost
• Contact management: Search, batch delete, detail panel with activity history
• Deal tracking: Create/delete deals with value and currency per contact
• Workflow integration: Import contacts from workflow step output directly into CRM

Quality

• Full i18n (English + Chinese) — zero hardcoded UI strings
• Multi-tenant isolation: All queries filter by tenant_id, workflow access verified via _can_access_workflow() helper
• Alembic migration for 5 new tables (workflows, workflow_steps, crm_contacts, crm_deals, crm_activities)

Files added/modified

File	Description
backend/app/models/workflow.py	Workflow + WorkflowStep SQLAlchemy models
backend/app/models/crm.py	CRMContact, CRMDeal, CRMActivity models
backend/app/api/workflows.py	Workflow REST API (CRUD, retry, chat, export)
backend/app/api/crm.py	CRM REST API (contacts, deals, activities, stats)
backend/app/services/workflow_orchestrator.py	Core workflow engine (plan, execute, summarize)
backend/app/main.py	Register workflow + CRM routers
backend/alembic/versions/add_workflow_crm_tables.py	Migration for 5 new tables
frontend/src/pages/WorkflowList.tsx	Workflow list page with create form
frontend/src/pages/WorkflowDetail.tsx	Workflow detail with steps, deliverables, chat
frontend/src/pages/CRMDashboard.tsx	CRM dashboard with pipeline + contacts views
frontend/src/App.tsx	Add routes for workflow and CRM pages
frontend/src/pages/Layout.tsx	Add sidebar navigation links
frontend/src/services/api.ts	Add workflowApi and crmApi
frontend/src/i18n/en.json	English translations for workflow + CRM
frontend/src/i18n/zh.json	Chinese translations for workflow + CRM

Test plan

• Run alembic upgrade head — verify 5 tables created
• Create a workflow — verify planning + execution + deliverable display
• Test workflow retry on failed steps
• Test CSV/PDF export from workflow step
• Create CRM contacts manually and via workflow import
• Drag deals between pipeline stages
• Switch language (EN/ZH) — verify no hardcoded strings
• Verify tenant isolation: User A cannot see User B's workflows/contacts

[wisdomqin]

Thanks for this substantial contribution! The Workflow Engine and CRM module are well-structured with good practices (i18n coverage, tenant isolation, retry logic).

However, we can't merge this into the core platform as-is. The main concern is that the workflow orchestrator is tightly coupled to a specific industry (foreign trade):

• AGENT_ROLES hardcodes 7 agent names (Leo, Ava, Marco, etc.) and their tools
• PLANNING_PROMPT is written specifically for trade workflows (market research → lead mining → outreach → PI generation)
• get_default_llm_model() picks a random enabled model without tenant scoping

Clawith is a general-purpose multi-agent platform, and core features need to work across all industries and use cases.

That said, we have a plugin/extension system on our roadmap. Once that's available, a trade-specific Workflow + CRM plugin would be a great fit — users who need it can install it, while the core platform stays industry-agnostic.

We'd love for you to publish this as a plugin when the system is ready. In the meantime, a few suggestions if you'd like to prepare for that:

1. Make the orchestrator generic — read agents and tools dynamically from the database instead of hardcoding
2. Move industry-specific prompts into configurable templates
3. Separate CRM into its own independent module
4. Use Depends(get_db) instead of async_session() directly in API routes (to match project conventions)

Looking forward to collaborating on this!