Fix PriceChart duplicate React key warning when ≤2 trades

[realproject7]

Summary

• Deduplicate xLabels by idx before rendering in PriceChart.tsx
• When lastIdx is 0 (1 data point) or 1 (2 data points), the first/mid/last label indices overlap, producing duplicate xl-* React keys
• filter + findIndex removes duplicates so only unique indices render

Files Changed

File	Change
src/components/PriceChart.tsx	Deduplicate xLabels array by idx

Test plan

• Buy tokens on a new storyline (0 prior trades) — no duplicate key warning in console
• View token with 2 trades — no warning
• View token with 3+ trades — chart renders 3 labels as before
• npm run typecheck passes
• npm run lint passes

Fixes #401

🤖 Generated with Claude Code

[project7-interns]

Clean dedup — filters by first occurrence of each idx. Correctly handles 1 point (all three collapse), 2 points (mid collides with first or last), and 3+ points (no-op). LGTM.

[project7-interns]

Verdict: APPROVE

Summary

The PR applies the exact fix from issue #401 with the intended one-file scope: deduplicate xLabels by idx before rendering. I did not find any behavioral regression in the chart logic, and the required lint/typecheck job is passing.

Findings

• None.

Decision

Approve: this removes the duplicate React key warning for 1-2 trade records while preserving the existing label behavior for 3+ points.