Build portfolio allocation visualization

[GuiBibeau]

User Story

As a portfolio user, I want an allocation visualization so that I can quickly understand how concentrated or diversified my portfolio is.

Context

This is the first visualization ticket. The goal is to add a useful chart or allocation panel that complements the dashboard without requiring full historical analytics.

Acceptance Criteria

• Portfolio allocation by asset is visualized in a clear chart or allocation module
• Percentage allocation is shown for priced assets
• Assets without price data are handled explicitly
• The visualization is responsive and accessible
• The implementation uses reusable data transformation logic
• The chart degrades gracefully for edge cases like one asset or many tiny assets

Notes

• A pie, donut, or bar visualization are all acceptable if justified well
• Prioritize readability and accessibility over flashy visuals
• This should set up future insights work, not block it

Out of Scope

• Historical performance charts
• Gain/loss tracking
• Tax analytics

Size

Medium