Updates ✨

• Added pagination to mailbox and sent mail GUIs, keeping each viewer's page state and exposing configurable previous/next buttons plus a page indicator.
• Introduced custom model data support across GUI decorations, command items, and mailings so resource-pack overrides display consistently in previews and persisted mail.
• Expanded composer and review screens with back buttons and editor shortcuts, making it easier to jump between the mailbox, sent list, and item editors while drafting mail.

Fixes 🛠️

• Apply configuration-driven item meta without overwriting existing lore or custom model data, preserving detailed previews for stored mail, decorations, and command bundles.
• Restored legacy command items by falling back to the generic action key when specialized metadata is missing, keeping older configurations clickable.

Changes 🔄

• Raised the default configuration schema to 1.6 and added pagination/back-button/custom-model entries throughout config.yml, alongside matching guidance in mailings.yml.
• SQLite storage now migrates mail_command_items to add a custom_model_data column and persists the optional value parallel to YAML command item definitions.

Notes 📌

• Use the command item editor's new custom model button to set a numeric model id or type CLEAR to reset, and update page button slots/materials to fit your layout before deployment.
• %current% and %total% placeholders populate the pagination indicator text; translate the new config messages/titles if you localize player-facing strings.
• If you upgraded from v1.5 or earlier, edit gui.main.items.mail-display.slots to free the bottom row (slots 37–44) so the next-page button has room; otherwise pagination controls stay hidden.
• Back up your data before upgrading so the automatic column migration and config updater can run safely, then /lmbreload to refresh GUI layouts after adjusting defaults.