feat: add tags (hashtag) support

[PeterRosdahl]

Summary

Adds first-class CLI support for Apple Reminders tags (hashtags). Addresses #18.

Apple Reminders stores tags as #hashtags embedded in the reminder title text. The EventKit API doesn't expose tags as a separate property, so this implementation parses trailing hashtags from the title and provides convenient CLI flags for managing them.

New features

tags subcommand

• remindctl tags — list all unique tags with counts
• remindctl tags shopping — list reminders matching a specific tag

--tag flag on add

• remindctl add "Buy milk" --tag shopping — creates with tag
• remindctl add "Urgent" --tag "shopping,groceries" — comma-separated
• remindctl add "Task" --tag a --tag b — repeatable

--tag, --remove-tag, --clear-tags on edit

• remindctl edit 1 --tag urgent — add tag(s)
• remindctl edit 1 --remove-tag old — remove specific tag(s)
• remindctl edit 1 --clear-tags — remove all tags

--tag filter on show

• remindctl show all --tag shopping — filter by tag

JSON output

Tags are now included in JSON output as a tags array and titleWithoutTags field:

{
  "title": "Buy milk #shopping #groceries",
  "titleWithoutTags": "Buy milk",
  "tags": ["shopping", "groceries"]
}

Implementation details

• Tag parsing (Models.swift): Computed tags and titleWithoutTags properties on ReminderItem that extract trailing #hashtags from the title
• Tag helpers (CommandHelpers.swift): Shared utilities for parsing CLI tag input, case-insensitive merge/remove, and title composition
• Tag validation: Tags must be alphanumeric (plus hyphens/underscores), rejecting invalid characters
• Tag matching is case-insensitive but preserves original casing in the stored title

Testing

• All existing tests pass
• swift build and swift test pass cleanly
• Manually tested: add, edit (add/remove/clear tags), show filter, tags list, JSON output, priority + tags combo

Changes

8 files changed, 298 insertions(+), 9 deletions(-)

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Merge tag edits from existing reminder tags

When tag flags are used together with --title, this path parses tags from the new title (title ?? reminder.title) instead of the current reminder, so existing tags are silently dropped before --tag/--remove-tag is applied. For example, editing a reminder that already has #work with edit 1 --title "New" --tag urgent ends up with only #urgent, which causes unintended tag loss whenever users combine title updates with tag updates.

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[steipete]

Thanks for the work here, but I am going to close this rather than merge.

I rechecked the current macOS SDK headers and EventKit still exposes no public Reminders tag or smart-list API. This PR implements tags by appending/parsing #hashtags in the reminder title, which would create remindctl-specific title text rather than native Reminders tags. That is too easy to confuse with real Apple Reminders tag support and would not drive native Smart Lists reliably.

If we want a helper around the notes-prefix convention some tools expose (#Tag | notes), that should be a separate, clearly named parsing/filtering feature, not first-class native tag support. Appreciate the effort.