fix: use date columns for Evernote timestamps in DB mode

[yaniv-golan]

Summary

• DB mode previously used created_time and last_edited_time column types, which are auto-managed by Notion and get overwritten on any page edit
• New schema uses explicit date columns prefixed with "Evernote" for all imported metadata, preserving original timestamps reliably
• Adds Evernote Author field (previously only available via --add-meta callout)
• Keeps Last Modified as Notion-native for tracking actual edits in Notion

New DB schema

Column	Type	Description
Title	Title	Note title
Evernote Tags	Multi-select	Tags from Evernote
Evernote URL	URL	Source URL
Evernote Created	Date	Original Evernote creation date
Evernote Updated	Date	Original Evernote last edit date
Evernote Author	Text	Note author
Evernote Imported	Created time	Import timestamp (auto)
Last Modified	Last edited time	Last Notion edit (auto)

Setup script

Includes scripts/create_notion_db.py using the official Notion API to create the database with correct schema + optional formula columns (Real Created, Real Updated) that bridge imported and native Notion notes.

Note on DB creation

Due to Notion internal API changes, programmatic database creation via submitTransaction no longer works. Users must pre-create the database either manually or using the provided script before running enex2notion --mode DB.

Test plan

• Manually verified with real ENEX import — Evernote Created/Updated preserved correctly across page edits
• Existing databases with old column names ("Tags") still detected via backwards-compatible lookup
• Setup script tested against Notion API