Feature Request: Filter transactions that have no tags (Untagged)

[twisterniq]

Describe the feature

On the Transactions page, add an "Untagged" option to the Tag filter, showing only transactions that have no tags assigned — similar to how "Uncategorized" already works for categories.

Ideally it should be combinable with other filters (date range, account, amount), like the existing tag filter is.

Why is this feature important?

Tags are typically assigned gradually over time, so a very common workflow is cleanup: finding everything that has not been organized yet.

Right now there is no way to answer "which transactions still need to be tagged?" other than going through the list manually, which does not scale once you have thousands of transactions. Since categories already offer this via "Uncategorized", extending the same idea to tags would feel consistent and cover a real gap in transaction hygiene workflows.

Additional context

• Related discussion about negative matching in rules: Feature Request: Support for more robust filters, including negative filters (!contains or !=) & AND/OR nesting, #530
• A "Transaction tag" condition for rules is being worked on in Feature: add a "Transaction tag" rule condition filter #2557 — this request is about the simpler case of the transactions page filter UI.