fix(viewer): handle multiple timestamp formats in days calculation

[abakane1]

Description

• Support milliseconds, microseconds, and seconds timestamp formats in days calculation
• Fixes incorrect days calculation (showing 36500 days) when timestamps use different formats

Changes

Modified apps/memos-local-openclaw/src/viewer/html.ts:

// Before: only handled milliseconds
if(e<1e12) e*=1000;

// After: handles all timestamp formats
if (e < 1e15 && e >= 1e12) e = Math.floor(e / 1000);  // microseconds to milliseconds
else if (e < 1e12) e *= 1000;  // seconds to milliseconds

Related Issue

N/A (found during local testing)