Extract hard-coded routes into centralized constants (resolves #747)

[BenjaminMichaelis]

Motivation

Hard-coded route strings were scattered across multiple frontend and backend files (useSiteShell.js, SidebarPanel.vue, SitemapXmlHelpers.cs, HomeController.cs), making route changes brittle and error-prone. Issue #747 specifically called out the isContentPage logic and suggested extracting routes into a constant and using Array.includes() for clarity.

Approach

Two new constant files serve as the single source of truth per layer:

Backend -- EssentialCSharp.Web/Constants/RouteConstants.cs

• StaticPages inner class with const string values for each non-content route
• NonContentRoutes HashSet for O(1) membership checks
• SeoMetadata.RouteConfig dictionary mapping routes to (ChangeFrequency, priority) tuples, replacing the two switch expressions in SitemapXmlHelpers.cs

Frontend -- EssentialCSharp.Web/src/constants/routes.js

• ROUTES object with named route constants
• NON_CONTENT_ROUTES array for Array.includes()/.some() checks
• NAVIGATION_LINKS array (with icon class, label, activePaths) replacing the inline definition in SidebarPanel.vue
• isContentPagePath() helper function for reuse

Consumers updated:

• useSiteShell.js -- isContentPage now uses NON_CONTENT_ROUTES.some() as the primary check, with percentComplete !== null as a secondary guard
• SidebarPanel.vue -- imports NAVIGATION_LINKS instead of defining the array inline
• SitemapXmlHelpers.cs -- GetChangeFrequencyForRoute / GetPriorityForRoute use dictionary lookup instead of switch expressions
• HomeController.cs -- [Route()] attributes reference RouteConstants.StaticPages constants

Notes

• The percentComplete !== null fallback is intentionally preserved in isContentPage so that pages not in the static list still correctly opt in/out of content-page features based on server-side data.
• Adding a new static page now requires updating only the two constant files; all consumers pick up the change automatically.

Closes #747

[Copilot]

Pull request overview

This PR centralizes previously hard-coded route strings into shared constants on both the frontend and backend to reduce brittleness and simplify future route updates (including the isContentPage logic called out in #747).

Changes:

• Added centralized route constants/config for backend (RouteConstants.cs) and frontend (routes.js).
• Updated frontend consumers (useSiteShell.js, SidebarPanel.vue) to use shared route/navigation constants.
• Updated sitemap and controller routing code (SitemapXmlHelpers.cs, HomeController.cs) to reference centralized constants.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
EssentialCSharp.Web/src/constants/routes.js	Adds frontend route constants, non-content route list, sidebar navigation definitions, and a reusable isContentPagePath() helper.
EssentialCSharp.Web/src/composables/useSiteShell.js	Switches isContentPage detection to use centralized NON_CONTENT_ROUTES logic.
EssentialCSharp.Web/src/components/SidebarPanel.vue	Replaces inline nav link definitions with imported NAVIGATION_LINKS.
EssentialCSharp.Web/Helpers/SitemapXmlHelpers.cs	Replaces switch expressions with lookup into centralized route SEO metadata config.
EssentialCSharp.Web/Controllers/HomeController.cs	Replaces hard-coded [Route] templates with RouteConstants.StaticPages.*.
EssentialCSharp.Web/Constants/RouteConstants.cs	Introduces backend centralized static routes, non-content route set, and sitemap SEO route metadata mapping.

Comments suppressed due to low confidence (3)

EssentialCSharp.Web/Helpers/SitemapXmlHelpers.cs:97

• Same key-normalization issue as GetChangeFrequencyForRoute: normalizedRoute strips the leading '/', but RouteConstants.SeoMetadata.RouteConfig keys include it (e.g. /guidelines). This makes the lookup always miss and forces the default priority (0.5) for every controller route.

    private static decimal GetPriorityForRoute(string route)
    {
        var normalizedRoute = route.TrimStart('/').ToLowerInvariant();
        
        if (RouteConstants.SeoMetadata.RouteConfig.TryGetValue(normalizedRoute, out var config))
        {
            return config.Item2;
        }
        
        return 0.5M;

EssentialCSharp.Web/Helpers/SitemapXmlHelpers.cs:85

• There are existing tests for GenerateSitemapXml, but none appear to validate the per-route ChangeFrequency/Priority values for controller routes (e.g., /guidelines priority 0.9, /termsofservice yearly). Adding assertions for these values would prevent regressions in the new RouteConfig lookup/normalization logic.

    private static ChangeFrequency GetChangeFrequencyForRoute(string route)
    {
        var normalizedRoute = route.TrimStart('/').ToLowerInvariant();
        
        if (RouteConstants.SeoMetadata.RouteConfig.TryGetValue(normalizedRoute, out var config))
        {
            return (ChangeFrequency)(int)config.Item1;
        }
        
        return ChangeFrequency.Monthly;

EssentialCSharp.Web/Constants/RouteConstants.cs:75

• IsContentPage currently does a direct NonContentRoutes.Contains(path) check, so paths like /home/ (trailing slash) or mixed-case inputs will be misclassified as content pages even though the frontend logic treats them as static. Consider normalizing path (trim whitespace, ensure leading '/', remove trailing '/', and handle null/empty) before checking the set.

    /// <summary>
    /// Determines if the given path represents a content page (from sitemap)
    /// versus a static page (non-content).
    /// </summary>
    public static bool IsContentPage(string path)
    {
        return !NonContentRoutes.Contains(path);
    }

[Copilot]

Pull request overview

Copilot reviewed 7 out of 7 changed files in this pull request and generated 2 comments.