Add Canadian stock universe

[dfdezdom]

Problem

InvestDayTip covers US, EU, and Asia but not Canada (TSX).

Expected

A new src/investdaytip/canada_universe.py module with ~20-30 large-cap Canadian tickers (e.g. Royal Bank, Shopify, Enbridge, etc.) using Yahoo Finance .TO suffix.

Hint

1. Create src/investdaytip/canada_universe.py with a CANADA_UNIVERSE list
2. Wire it into recommender._build_universe() following the pattern of ASIA_UNIVERSE