[aicayzer]

What changes for a person

You can now add and remove an item's tags in MAPP. Before, tags were read-only.

• Inspector: a Tags section lists the item's tags, each with a remove button, and a field to add one. The field suggests tags already used in the library.
• Menu and palette: Add Tag… is in the item menus (menu bar, context menu, More menu, board cards) and the command palette. It opens a small sheet and works for several selected items at once.
• Offline and undo: tag changes are queued like MAPP's other edits, show at once, and undo and redo.

What I chose

• The favorite tag stays with the Favorite command: it is not listed in the tag editor, cannot be removed there, and is refused as typed text. The conflicted-copy tag is treated the same way.
• Typed tags are trimmed and keep their case. A tag is refused if it is empty, longer than 128 characters, or is . or .., and an item can hold at most 100. The refusal appears under the field and the typed text stays.
• An item in Recently Deleted, or one with a problem, shows its tags without remove buttons or a field.
• Removing a tag another device already removed sends nothing. A change the server refuses is told in the usual notice.
• The old fallback that listed tags under Details is gone, since Tags now shows them.
• String Catalog: only the new strings were added. Building in Xcode also reformatted the whole file and added unrelated missing entries, so I kept just this work's keys.

Tested

The Unit plan passes, including new tests for add, remove, duplicate, invalid and reserved tags, a full item, an item in the bin, suggestions, queued writes with undo and redo, and a refused write.

Not tested: the Live plan (no instance was given), so offline queueing across a restart rests on the existing queue and is not exercised here. The UI plan was not run. The inspector controls were looked at only briefly in the sample library; adding a tag with Return from the field was not exercised in the running app.