Introduce a new highlight.js language definition for Kusto (KQL) at src/.../highlight.kusto.js. The file declares keywords, types, built-in functions and token patterns (strings, numbers, variables, comments, etc.). Also update post.highlight.mjs to import and register the new 'kusto' language so Kusto code blocks are highlighted in posts.

Add Kusto to TinyMCE codesample_languages so authors can select it in the editor (src/Moonglade.Web/wwwroot/js/app/admin.editor.module.mjs). Update AGENTS.md with guidance to register new highlight.js languages before hljs.highlightElement in src/Moonglade.Web/wwwroot/js/app/post.highlight.mjs and add them to the editor list. Bump AssemblyVersion/FileVersion to 15.17.0 and set Version to 15.17.0-preview.1 in src/Directory.Build.props.

Add a new FEATURE-ROADMAP.md that documents feature research, prioritized batches, and implementation notes for Moonglade (prepared 2026-06-08). Update AGENTS.md to add a documentation/licensing guideline requiring repository content to be written in English except for localization resources (e.g., *.resx or third-party language packs).

Extend search capabilities end-to-end. Backend: expand SearchPostQuery into a richer query (keyword, paging, category, tag, language, date range, sort) and return SearchPostQueryResult (Posts + TotalRows). Add SearchPostSort enum and refactor handler to normalize keywords, apply keyword and facet filters, count total rows, apply sorting and paging. UI: update Search.cshtml to provide a search form with sort, category/tag/language/date filters, paging controls, and localization support; wire the page to call the enhanced query and build PagedResult. Presentation: improve _PostListEntry highlighting to HTML-encode text and safely mark matched terms. Tests: update expectations and add tests for pagination/sorting and facet filtering; adjust test helper to accept languageCode. Docs: permit non-English values in unit tests and update roadmap note to avoid scanning full post bodies. Overall: implements safer highlighting, richer filtering/sorting, and paginated search results with UI and tests.

Replace hard-coded labels and option text in Search.cshtml with SharedLocalizer lookups (Sort, sort options, All categories, All tags, All languages, Published from/to, Clear and the result(s) message). Add corresponding translations for those keys in Program.resx for de-DE, ja-JP, zh-Hans and zh-Hant. No functional changes — this prepares the Search page for localization and uses localized plural formatting for the results count.

Expose post LastModifiedUtc in PostOperationResult and controller responses; include LastModifiedUtc when saving posts. Add auto-save feature in the post editor: UI toggle, CSS styling, persistent setting, interval timer, snapshot/validation logic and background save flow. Introduce localized strings and wire getLocalizedString into editor, form, schedule and slug mixins; update EditPost view to use SharedLocalizer and embed localized strings. Update multiple .resx resource files (de, ja, zh-Hans, zh-Hant) with new keys. Minor refactors: extract request/snapshot helpers and savePost method, and replace hardcoded messages with localized messages.

Expose post LastModifiedUtc in PostOperationResult and controller
responses; include LastModifiedUtc when saving posts. Add auto-save
feature in the post editor: UI toggle, CSS styling, persistent setting,
interval timer, snapshot/validation logic and background save flow.
Introduce localized strings and wire getLocalizedString into editor,
form, schedule and slug mixins; update EditPost view to use
SharedLocalizer and embed localized strings. Update multiple .resx
resource files (de, ja, zh-Hans, zh-Hant) with new keys. Minor
refactors: extract request/snapshot helpers and savePost method, and
replace hardcoded messages with localized messages.

Add comprehensive SearchPageTests to verify search page rendering, query-string state preservation, pagination links, and redirect behavior when requested pages exceed available results. Register Microsoft.AspNetCore.TestHost in the test project to run the app via TestServer, and mock query mediator/cache to drive scenarios. Also update FEATURE-ROADMAP.md to mark optional web tests for the search page as completed.

Introduce a configurable rate limiter for webmention sources. Adds WebmentionSourceRateLimitOptions (Enabled, PermitLimit=10, WindowMinutes=10 with validation) and WebmentionSourceRateLimiter which implements TryAcquire(Uri) and enforces a per-source-host fixed time window using a ConcurrentDictionary of counters and a lock per counter. The limiter uses IOptionsMonitor, TimeProvider and logs a warning when a host exceeds its permit limit.

Introduce unit tests for WebmentionSourceRateLimiter covering: enforcement of per-source host permit limits, independent tracking of different source hosts, and behavior when the limiter is disabled. Tests use Moq to provide IOptionsMonitor<WebmentionSourceRateLimitOptions>, TimeProvider.System, and a mocked ILogger.

Introduce source-based rate limiting for Webmentions. Adds Webmention:SourceRateLimit options to appsettings, registers WebmentionSourceRateLimiter and TimeProvider in DI, and wires the limiter into the receive flow (ReceiveWebmentionCommandHandler returns SourceRateLimitExceeded when TryAcquire fails). Controller maps the new status to HTTP 429. WebmentionResponse and enum updated, service registration updated to accept IConfiguration, and tests extended to cover the rate-limit behavior. Also marks the feature as completed in FEATURE-ROADMAP.

Replace hard-coded admin and footer text with SharedLocalizer and localized data attributes, add hidden localized string containers for JS, and switch various UI labels, placeholders and aria labels to use localization. Update multiple admin pages (Comments, Draft, EditPage, LocalAccount, Menu, Post, Settings, Widgets, Shared footer) and corresponding client JS modules to consume localized strings. Mark JavaScript localization tasks as done in FEATURE-ROADMAP and add/expand resource entries (Program.*.resx) for supported locales.

Upgrade various Microsoft package references across multiple projects to apply patch updates. EF Core packages (Microsoft.EntityFrameworkCore, Relational, SqlServer, InMemory, Sqlite) moved from 10.0.8 to 10.0.9; Microsoft.Extensions.Http.Resilience updated from 10.6.0 to 10.7.0; Microsoft.Extensions.Diagnostics.HealthChecks.EntityFrameworkCore and Microsoft.Extensions.Logging.AzureAppServices to 10.0.9; test-related packages (Microsoft.AspNetCore.DataProtection, System.Security.Cryptography.Xml, Microsoft.AspNetCore.TestHost) also bumped to 10.0.9. Affected projects include Moonglade.Data.PostgreSql, Moonglade.Data.SqlServer, Moonglade.Data, Moonglade.Email.Client, Moonglade.IndexNow.Client, Moonglade.Moderation, Moonglade.Web, Moonglade.Webmention and multiple test projects. These updates keep dependencies consistent and ensure the latest patch fixes are applied.

Promote the build from beta to release candidate by updating the <Version> property in src/Directory.Build.props from 15.17.0-beta.1 to 15.17.0-rc.1. This prepares the project for an RC release.

Update src/Directory.Build.props to remove the prerelease suffix and set <Version> to 15.17.0. This promotes the package from the 15.17.0-rc.1 release candidate to the stable 15.17.0 release.