CodexScope v0.1.6

Adds an all-history overview range.

• Adds a 历史 date filter next to 30天内.
• The history range uses every exported local record, from the earliest log event to the latest one.
• Changes the generator default to export all local history; --days N still works for bounded exports.
• Adds tests for all-history cutoff and cache-window behavior.

Checks:

• go test ./...
• npm run build:frontend
• npm run release:local
• Browser check: 历史总览 · 48,061 次 on local data