Add cloud hosting cost estimate documentation

planning/CLOUD_COST_ESTIMATE.md

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+# Cloud Hosting Cost Estimate
+
+This document provides cost estimates for running the PBS Wisconsin Editorial Assistant v3.0 in cloud infrastructure versus locally.
+
+## Architecture Summary
+
+- **FastAPI backend** (Python 3.13, async)
+- **React web dashboard** (Vite/TypeScript)
+- **SQLite database** (~2.7 MB currently)
+- **Background job worker** (single-worker polling loop)
+- **MCP server** for Claude Desktop integration
+
+---
+
+## Infrastructure Cost Options
+
+| Option | Monthly Cost | Best For |
+|--------|-------------|----------|
+| **VPS (DigitalOcean/Linode)** | $8-15 | Getting started, low volume |
+| **AWS EC2 (t3.small)** | $25-35 | Scalability, managed backups |
+| **Home VM via Proxmox** | $15-30 | Already have hardware |
+
+### What's included in infrastructure
+
+- 1-2 vCPU, 1-2 GB RAM (sufficient for single-worker)
+- 50 GB storage for outputs/transcripts
+- Basic backup/snapshot service
+
+---
+
+## Variable Costs (LLM API)
+
+The **LLM API costs dominate** (75-90% of operational costs):
+
+| Model Tier | Cost per 1M tokens | Typical Job Cost |
+|------------|-------------------|------------------|
+| Gemini 2.5 Flash (default) | $0.15 in / $0.60 out | $0.02-0.10 |
+| Gemini 1.5 Pro (big-brain) | $1.25 in / $5.00 out | $0.10-0.50 |
+| Claude 3.5 Sonnet (premium) | $3.00 in / $15.00 out | $0.25-1.00 |
+
+### Built-in Cost Controls
+
+The system has built-in cost controls configured in `config/llm-config.json`:
+
+- `DEFAULT_RUN_COST_CAP = $1.0` per job
+- `DEFAULT_MAX_COST_PER_1K_TOKENS = $0.05`
+- Tiered model selection (cheap models first, escalate on failure)
+
+---
+
+## Total Monthly Cost Estimates
+
+| Scenario | Jobs/Month | Infrastructure | LLM API | **Total** |
+|----------|-----------|----------------|---------|-----------|
+| Light use | 50 | $12 (VPS) | $5 | **~$17/mo** |
+| Moderate | 200 | $12 (VPS) | $20 | **~$32/mo** |
+| Heavy | 500 | $30 (AWS) | $50 | **~$80/mo** |
+| Production | 1000 | $35 (AWS) | $150 | **~$185/mo** |
+
+---
+
+## Additional Costs
+
+| Item | Cost | Notes |
+|------|------|-------|
+| Langfuse (LLM observability) | $0-20/mo | Optional, useful for debugging |
+| Cloudflare Tunnel | $0 | Free tier sufficient |
+| Automated backups | $1-5/mo | Essential for production |
+| Domain/SSL | $0-5/mo | Cloudflare free, or Route 53 |
+
+---
+
+## Deployment Options
+
+### Option A: Home VM (Proxmox)
+
+**Monthly Cost: $15-30 (+ LLM API)**
+
+- Electricity: $5-10
+- Hardware depreciation: $10-20
+- Maintenance: 2 hrs/month
+
+Best for: Initial development and testing
+
+### Option B: Cloud VPS (DigitalOcean/Linode/Vultr)
+
+**Monthly Cost: $8-15/month (+ LLM API + backups)**
+
+- VPS (1-2 vCPU, 1-2 GB RAM): $6-12
+- Backups: $1-2
+- Maintenance: 1 hr/month
+
+Best for: Low-to-moderate volume production use
+
+### Option C: AWS EC2/ECS
+
+**Monthly Cost: $25-35/month (+ LLM API)**
+
+- t3.small instance: $15-20
+- EBS storage (50 GB): $5
+- Data transfer: $5-10
+- DNS (Route 53): $1
+
+Best for: Scalability, enterprise requirements
+
+### Option D: Station Infrastructure (Future)
+
+**Monthly Cost: $0 (IT handles)**
+
+- VM allocation, power, network included
+- IT support included
+- Requires: 1-2 months stable operation first
+- Prerequisite: Complete runbooks, cost projections, handoff docs
+
+---
+
+## Scaling Considerations
+
+### Current Design Limits
+
+- **Single-worker architecture:** Processes 1 job at a time (by default)
+- **SQLite concurrency:** Limited to 5 concurrent database sessions
+- **Memory per job:** ~100-500 MB for large transcripts
+- **API server capacity:** ~50-100 concurrent WebSocket connections
+
+### When to Scale
+
+| Trigger | Action | Additional Cost |
+|---------|--------|-----------------|
+| Queue depth > 20 regularly | Add workers | +$5-10/mo per worker |
+| >500 jobs/month | Consider PostgreSQL | +$15-25/mo (RDS) |
+| >1000 jobs/month | Multi-region/HA | +$50-100/mo |
+
+---
+
+## Recommendations
+
+### For Minimal Cost
+
+- Start with a **$8-12/mo VPS** (Linode, Vultr, or DigitalOcean)
+- Keep SQLite (good for <500 jobs/month)
+- Use Cloudflare Tunnel for secure access (free)
+- Stick to Gemini Flash tier for most jobs
+
+### For Production Reliability
+
+- AWS EC2 t3.small (~$25/mo) with daily EBS snapshots
+- Migrate to PostgreSQL if exceeding 1000 jobs/month
+- Set up monitoring/alerting for disk space and error rates
+- Implement centralized logging
+
+---
+
+## Production Readiness Checklist
+
+For cloud deployment, ensure the following are in place:
+
+- [ ] Database backup strategy (daily automated snapshots)
+- [ ] Monitoring & alerting (disk space, error rates, LLM API errors)
+- [ ] Log aggregation (centralized logging service)
+- [ ] Rate limiting (per-user, per-IP to prevent abuse)
+- [ ] HTTPS/TLS (SSL termination, certificate management)
+- [ ] Authentication (Cloudflare Access or OAuth)
+- [ ] Cost caps & alerts (OpenRouter API limits, budget notifications)
+- [ ] Disaster recovery (backup + restore procedures)
+
+---
+
+## Summary
+
+**Bottom line:** Expect **$15-40/month** for light-to-moderate use, with LLM API costs scaling linearly based on job volume and transcript length. Infrastructure costs are relatively fixed; the main variable is how many jobs you process and which model tiers they require.
+
+| Cost Component | % of Total | Controllable? |
+|----------------|-----------|---------------|
+| LLM API | 75-90% | Yes (model selection, failure reduction) |
+| Compute | 5-15% | Somewhat (right-size instances) |
+| Storage | 2-5% | Yes (archival policies) |
+| Network | 1-3% | Limited |
+
+---
+
+*Last updated: 2026-02-09*