Purpose

This PR replaces hardcoded “no suggestions” placeholders with dynamic ML-based titles and messages, introduces a user authentication flag for controlling placeholder visibility, and cleans up obsolete resources and minor documentation whitespace.

• Swap out BoxPlaceholder/NoItemsPlaceholder for TitlePlaceholder/MessagePlaceholder with bindings and a DataTrigger for DisplayAutocompleteMLStaticPage
• Add IsUserAuthenticated property in the ViewModel to gate ML content based on login state
• Remove old resource entries and update core resource strings for consistency
• Clean up trailing blanks in the Node Autocomplete documentation HTML

Declarations

Check these if you believe they are true

• Is documented according to the standards
• The level of testing this PR includes is appropriate
• User facing strings, if any, are extracted into *.resx files
• Snapshot of UI changes, if any.
• Changes to the API follow Semantic Versioning and are documented in the API Changes document.
• This PR modifies some build requirements and the readme is updated
• This PR contains no files larger than 50 MB
• This PR introduces new feature code involve network connecting and is tested with no-network mode.

Release Notes

(FILL ME IN) Brief description of the fix / enhancement. Use N/A to indicate that the changes in this pull request do not apply to Release Notes. Mandatory section

Reviewers

@DynamoDS/synapse

FYIs

@Jingyi-Wen