- New lib/notes.ts: localStorage key `notes:<code>` storing { text, updatedAt },
2000-char cap, blank/whitespace removes the key.
- New InvestmentNote sidebar panel: textarea + character counter, save button
enabled only when dirty, "방금 전 / N분 전 / 오늘 HH:MM / YYYY-MM-DD"
relative timestamp on the last save, short save-confirmation toast.
- Mounted in [code]/page.tsx sidebar after AlertsPanel.
Also tightens writeTargets() to require strictly positive finite values,
matching the UI's parseNum() guard so the lib is safe under direct external
calls (reviewer's non-blocking note on a4a4a7f).
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
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