Phase 5: AI investment planning - CD rate fetcher and AI recommendation engine

- Add shared.cd_rates table for cross-tenant market data (CD rates from Bankrate)
- Create standalone Puppeteer scraper script (scripts/fetch-cd-rates.ts) for cron-based rate fetching
- Add investment-planning backend module with 3 endpoints: snapshot, cd-rates, recommendations
- AI service gathers tenant financial data (accounts, investments, budgets, projects, cash flow) and calls OpenAI-compatible API (NVIDIA endpoint) for structured investment recommendations
- Create InvestmentPlanningPage with summary cards, current investments table, market CD rates table, and AI recommendation accordion
- Add Investment Planning to sidebar under Planning menu
- Configure AI_API_URL, AI_API_KEY, AI_MODEL environment variables

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

.env.example

@@ -5,3 +5,8 @@ DATABASE_URL=postgresql://hoafinance:change_me@postgres:5432/hoafinance
 REDIS_URL=redis://redis:6379
 JWT_SECRET=change_me_to_random_string
 NODE_ENV=development
+
+# AI Investment Advisor (OpenAI-compatible API)
+AI_API_URL=https://integrate.api.nvidia.com/v1
+AI_API_KEY=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
+AI_MODEL=moonshotai/kimi-k2.5