[jinskjoy]

Summary

This pull request introduces search autocomplete suggestions, recent search history, and an integrated search filters quick-reference modal for Mailpit's web UI:

• Filter Suggestions: Autocompletes supported search filters (to:, from:, subject:, cc:, bcc:, reply-to:, addressed:, message-id:, is:, has:, tag:, before:, after:, larger:, smaller:, and negations ! / -). Suggestions are categorized by fields, status & content, dates & sizes, and dynamic tags loaded from the mailbox.
• Recent Search History: Saves searches locally (localStorage key mp-search-history, up to 50 items). The default view displays the 5 most recent searches, while typing searches through all matching history items. Individual items or all history can be removed.
• Search Filters Modal: Adds a quick-reference modal (#SearchFiltersModal) accessible from the autocomplete footer, detailing all available search syntax, descriptions, and clickable examples that immediately apply the filter.
• Web UI Setting: Adds a toggle option in App Settings ("Show search autocomplete suggestions", enabled by default) allowing users to disable the suggestions dropdown if desired (localStorage key mp-hide-search-suggestions).
• Keyboard Navigation & Usability: Full keyboard navigation (↓ / ↑ to cycle, Enter / Tab to apply, Esc to dismiss). Keystrokes do not pre-select suggestions so pressing Enter without arrow navigation submits the raw typed query directly.

Screenshots

Related issues

None

Type of change

• Bug fix
• New feature
• Refactor / code cleanup
• Documentation
• Other (please describe):

Test plan

• Tested search autocomplete with various prefixes (to:, from:, is:, has:, tag:, larger:, !is:).
• Verified recent searches persistence (up to 50 items stored, 5 shown in default view, matches filtered on typing).
• Tested keyboard navigation (↓, ↑, Enter, Tab, Esc).
• Verified pressing Enter without arrow navigation submits the typed query rather than selecting a suggestion.
• Verified settings toggle in Web UI settings enables/disables the autocomplete dropdown.
• Verified Search Filters modal opens from the dropdown footer, external documentation link has no duplicate icons, and clicking examples applies them.
• Tested in light, dark, and deep-dark themes.
• Linter (npm run lint) passes with 0 warnings/errors; npm run build and go test ./... pass.

AI assistance disclosure

Please indicate whether AI tools (e.g. Claude, Copilot, ChatGPT, Cursor) were used in preparing this pull request:

• No AI was used
• Assisted — AI was used for suggestions, explanations, or small snippets, but the code was primarily written and understood by me
• Extensive — AI generated a significant portion of the code in this PR

If AI was used, briefly describe how (which tools, and for what parts):

Used Google Antigravity to implement the Vue components, filter matching logic, keyboard navigation, and Bootstrap styling.

Checklist

• I have tested my changes locally
• I have read and understood all code being submitted (including any AI-generated portions)
• Documentation has been updated where relevant

[axllent]

This is awesome, thanks! This is a large commit so it'll take me a few days to properly review and test, however I can see this will be a valuable contribution.

[jinskjoy]

Thank you. Please let me know if any changes needs to be done.