Show closest word suggestion when translation or conjugation is invalid

Terms

• I have searched open and closed feature requests
• I agree to follow Scribe-iOS' Code of Conduct

Description

Summary

When a user enters a word that isn't found during Translate or Conjugate, Scribe currently shows a generic "invalid" error with no further guidance. Users are left with no idea whether they made a typo or the word simply doesn't exist in the database.

Problem

The invalid state (commandState = .invalid) gives zero actionable feedback. A user who types "hause" instead of "Haus" gets the same error as someone who types complete nonsense — no distinction, no hint.

Proposed Solution

Reuse the existing queryAutocompletions infrastructure to find the closest matching word when a command returns invalid, and display it in the command bar as:

"Did you mean: Haus?"

This covers both Translate and Conjugate commands since both already funnel through commandState = .invalid.

Affected Files

Notes

• LanguageDBManager.shared.queryAutocompletions(word:) already returns close matches — no new DB queries needed
• Purely additive, no existing logic removed
• Strings can be hard-coded for now pending i18n entry

Start by tracing the existing queryAutocompletions flow and invalid command handling in Translate.swift and Conjugate.swift. Then inspect CommandVariables.swift and KeyboardViewController.swift to see how command-bar state is represented and rendered. Done means invalid Translate and Conjugate inputs can show the closest matching word as a “Did you mean” suggestion without removing existing behavior.