Elternbeirat.PocketBase/PocketBaseClient.cs

@@ -38,14 +38,11 @@ public sealed class PocketBaseClient(HttpClient httpClient)
     /// <returns>
     ///     The public pages, or an empty list if there are none.
     /// </returns>
-    /// <exception cref="HttpRequestException">
-    ///     PocketBase could not be reached or returned a non-success status code.
-    /// </exception>
-    /// <exception cref="JsonException">
-    ///     The response could not be deserialized.
+    /// <exception cref="PocketBaseUnavailableException">
+    ///     PocketBase could not be reached, timed out, or returned an unreadable response.
     /// </exception>
     /// <exception cref="OperationCanceledException">
-    ///     <paramref name="token"/> was canceled or the request timed out.
+    ///     <paramref name="token"/> was canceled by the caller.
     /// </exception>
     public Task<IReadOnlyList<Page>> GetPagesAsync(CancellationToken token = default)
         => GetRecordsAsync<Page>("pages", "order", token);
@@ -73,15 +70,22 @@ public sealed class PocketBaseClient(HttpClient httpClient)
         => GetRecordsAsync<Event>("events", "start", token);
 
     /// <summary>
-    ///     Gets all public FAQ entries, ordered by <see cref="Faq.Topic"/>.
+    ///     Gets all public FAQ entries, ordered by <see cref="Faq.Topic"/>, then by
+    ///     <see cref="Faq.Question"/>.
     /// </summary>
+    /// <remarks>
+    ///     The second sort key makes the order total: sorting by topic alone leaves
+    ///     entries within a topic in an undefined order, so the same content could
+    ///     render differently between requests. Adding the question as a tie-breaker
+    ///     keeps the FAQ list and any teaser drawn from it stable.
+    /// </remarks>
     /// <inheritdoc cref="GetPagesAsync" path="/param"/>
     /// <returns>
     ///     The public FAQ entries, or an empty list if there are none.
     /// </returns>
     /// <inheritdoc cref="GetPagesAsync" path="/exception"/>
     public Task<IReadOnlyList<Faq>> GetFaqsAsync(CancellationToken token = default)
-        => GetRecordsAsync<Faq>("faqs", "topic", token);
+        => GetRecordsAsync<Faq>("faqs", "topic,question", token);
 
     /// <summary>
     ///     Gets all public records of a collection in a single request.
@@ -101,6 +105,12 @@ public sealed class PocketBaseClient(HttpClient httpClient)
     /// <returns>
     ///     The public records, or an empty list if there are none.
     /// </returns>
+    /// <exception cref="PocketBaseUnavailableException">
+    ///     PocketBase could not be reached, timed out, or returned an unreadable response.
+    /// </exception>
+    /// <exception cref="OperationCanceledException">
+    ///     <paramref name="token"/> was canceled by the caller.
+    /// </exception>
     private async Task<IReadOnlyList<T>> GetRecordsAsync<T>(
         string collection,
         string sort,
@@ -112,7 +122,25 @@ public sealed class PocketBaseClient(HttpClient httpClient)
                   + $"?perPage=500&filter={Uri.EscapeDataString("public=true")}"
                   + $"&sort={Uri.EscapeDataString(sort)}";
 
+        try
+        {
             var result = await httpClient.GetFromJsonAsync<RecordList<T>>(url, token);
             return result?.Items ?? [];
         }
+        // These three mean PocketBase itself failed: it was unreachable
+        // (HttpRequestException), the request to it timed out (a TaskCanceledException
+        // whose inner exception is a TimeoutException, which is how HttpClient surfaces
+        // its own timeout), or it answered with something we could not read
+        // (JsonException). A plain TaskCanceledException with no inner TimeoutException
+        // is the caller's own cancellation via token and is deliberately not caught --
+        // it propagates as OperationCanceledException so an aborted request stays an
+        // abort, not a fault.
+        catch (Exception exception) when (
+            exception is HttpRequestException
+                or JsonException
+                or TaskCanceledException { InnerException: TimeoutException })
+        {
+            throw new PocketBaseUnavailableException($"Could not read collection '{collection}'.", exception);
+        }
+    }
 }

Elternbeirat.PocketBase/PocketBaseUnavailableException.cs

@@ -0,0 +1,49 @@
+namespace Elternbeirat.PocketBase;
+
+/// <summary>
+///     Thrown when PocketBase could not be reached, timed out, or returned a
+///     response that could not be read.
+/// </summary>
+/// <remarks>
+///     This is the one failure the content pages need to distinguish: the site is
+///     up but its data store is not, which is an HTTP 503, not a 404. Which
+///     low-level exceptions mean that (a transport error, a timeout, unreadable
+///     JSON) is <see cref="PocketBaseClient"/>'s concern; callers catch only this
+///     type and need not know how the client talks to PocketBase.
+/// </remarks>
+public sealed class PocketBaseUnavailableException : Exception
+{
+    /// <summary>
+    ///     Initializes a new instance with a default message.
+    /// </summary>
+    public PocketBaseUnavailableException()
+        : base("PocketBase is unavailable.")
+    {
+    }
+
+    /// <summary>
+    ///     Initializes a new instance with the given message.
+    /// </summary>
+    /// <param name="message">
+    ///     The message that describes the error.
+    /// </param>
+    public PocketBaseUnavailableException(string message)
+        : base(message)
+    {
+    }
+
+    /// <summary>
+    ///     Initializes a new instance with the given message and the underlying
+    ///     failure that caused it.
+    /// </summary>
+    /// <param name="message">
+    ///     The message that describes the error.
+    /// </param>
+    /// <param name="innerException">
+    ///     The transport, timeout, or deserialization exception that was caught.
+    /// </param>
+    public PocketBaseUnavailableException(string message, Exception innerException)
+        : base(message, innerException)
+    {
+    }
+}

Elternbeirat.Web/Components/Layout/MainLayout.razor.cs

@@ -6,14 +6,19 @@ namespace Elternbeirat.Web.Components.Layout;
 
 public partial class MainLayout
 {
-    [LoggerMessage(Level = LogLevel.Warning, Message = "Could not load navigation pages from PocketBase.")]
-    private static partial void LogLoadFailed(ILogger logger, Exception exception);
+    [LoggerMessage(
+        Level = LogLevel.Warning,
+        Message = "Could not load navigation pages from PocketBase; the menu is empty.")]
+    private static partial void LogSourceUnavailable(ILogger logger, Exception exception);
 
     [Inject]
-    private PocketBaseClient PocketBase { get; set; } = default!;
+    private PocketBaseClient PocketBase { get; set; } = null!;
 
     [Inject]
-    private ILogger<MainLayout> Logger { get; set; } = default!;
+    private ILogger<MainLayout> Logger { get; set; } = null!;
+
+    [CascadingParameter]
+    private HttpContext? HttpContext { get; set; }
 
     private IReadOnlyList<NavLinkItem> _header = [];
     private IReadOnlyList<NavLinkItem> _footer = [];
@@ -22,15 +27,15 @@ public partial class MainLayout
     {
         try
         {
-            var pages = await PocketBase.GetPagesAsync();
+            var pages = await PocketBase.GetPagesAsync(HttpContext?.RequestAborted ?? default);
             _header = NavBuilder.Header(pages);
             _footer = NavBuilder.Footer(pages);
         }
-        catch (HttpRequestException ex)
+        catch (PocketBaseUnavailableException ex)
         {
-            // Source unreachable -> render the chrome with an empty menu instead of
-            // a 500. The brand link still leads home.
-            LogLoadFailed(Logger, ex);
+            // Only the menu fails: render the chrome with an empty menu instead of a
+            // 500, so every page stays reachable. The brand link still leads home.
+            LogSourceUnavailable(Logger, ex);
         }
     }
 }

Elternbeirat.Web/Features/Embeds/EventsEmbed.razor

@@ -1,12 +1,7 @@
+@if (_upcoming.Count > 0)
+{
     <section class="embed embed-events">
         <h2>Kommende Termine</h2>
-
-    @if (_upcoming.Count == 0)
-    {
-        <p>Zurzeit sind keine Termine geplant.</p>
-    }
-    else
-    {
         <ul class="event-list">
             @foreach (var ev in _upcoming)
             {
@@ -21,5 +16,5 @@
             }
         </ul>
         <p class="embed-more"><a href="/events">Alle Termine <span aria-hidden="true">&rarr;</span></a></p>
-    }
     </section>
+}

Elternbeirat.Web/Features/Embeds/EventsEmbed.razor.cs

@@ -6,14 +6,24 @@ namespace Elternbeirat.Web.Features.Embeds;
 
 public partial class EventsEmbed
 {
-    [LoggerMessage(Level = LogLevel.Warning, Message = "Could not load events for an embed from PocketBase.")]
-    private static partial void LogLoadFailed(ILogger logger, Exception exception);
+    // Number of upcoming events shown in the teaser; the full list is one link away.
+    private const int TeaserCount = 3;
+
+    [LoggerMessage(
+        Level = LogLevel.Warning,
+        Message = "Could not load events for an embed from PocketBase; the teaser is omitted.")]
+    private static partial void LogSourceUnavailable(
+        ILogger logger,
+        Exception exception);
 
     [Inject]
-    private PocketBaseClient PocketBase { get; set; } = default!;
+    private PocketBaseClient PocketBase { get; set; } = null!;
 
     [Inject]
-    private ILogger<EventsEmbed> Logger { get; set; } = default!;
+    private ILogger<EventsEmbed> Logger { get; set; } = null!;
+
+    [CascadingParameter]
+    private HttpContext? HttpContext { get; set; }
 
     private IReadOnlyList<Event> _upcoming = [];
 
@@ -22,22 +32,25 @@ public partial class EventsEmbed
         IReadOnlyList<Event> events;
         try
         {
-            events = await PocketBase.GetEventsAsync();
+            events = await PocketBase.GetEventsAsync(HttpContext?.RequestAborted ?? CancellationToken.None);
         }
-        catch (HttpRequestException ex)
+        catch (PocketBaseUnavailableException exception)
         {
-            // Source unreachable -> show no teaser instead of a 500.
-            LogLoadFailed(Logger, ex);
+            // Only part of the page fails: omit the teaser, keep the page (and its
+            // 200) intact. A missing teaser is degraded, not broken.
+            LogSourceUnavailable(Logger, exception);
             return;
         }
 
-        // Teaser: the three soonest upcoming events, earliest first. An event
-        // earlier today still counts as upcoming.
+        // Teaser: the soonest upcoming events, earliest first. An event earlier
+        // today still counts as upcoming.
         var today = DateOnly.FromDateTime(DateTime.Today);
-        _upcoming = events
-            .Where(e => DateOnly.FromDateTime(e.Start) >= today)
-            .OrderBy(e => e.Start)
-            .Take(3)
-            .ToList();
+        _upcoming =
+        [
+            .. events
+                .Where(@event => DateOnly.FromDateTime(@event.Start) >= today)
+                .OrderBy(@event => @event.Start)
+                .Take(TeaserCount)
+        ];
     }
 }

Elternbeirat.Web/Features/Embeds/FaqsEmbed.razor

@@ -1,12 +1,7 @@
+@if (_faqs.Count > 0)
+{
     <section class="embed embed-faqs">
         <h2>Häufige Fragen</h2>
-
-    @if (_faqs.Count == 0)
-    {
-        <p>Zurzeit gibt es keine Fragen.</p>
-    }
-    else
-    {
         @foreach (var faq in _faqs)
         {
             <details class="faq-item">
@@ -17,5 +12,5 @@
             </details>
         }
         <p class="embed-more"><a href="/faqs">Alle Fragen <span aria-hidden="true">&rarr;</span></a></p>
-    }
     </section>
+}

Elternbeirat.Web/Features/Embeds/FaqsEmbed.razor.cs

@@ -6,14 +6,24 @@ namespace Elternbeirat.Web.Features.Embeds;
 
 public partial class FaqsEmbed
 {
-    [LoggerMessage(Level = LogLevel.Warning, Message = "Could not load FAQs for an embed from PocketBase.")]
-    private static partial void LogLoadFailed(ILogger logger, Exception exception);
+    // Number of questions shown in the teaser; the full hub is one link away.
+    private const int TeaserCount = 3;
+
+    [LoggerMessage(
+        Level = LogLevel.Warning,
+        Message = "Could not load FAQs for an embed from PocketBase; the teaser is omitted.")]
+    private static partial void LogSourceUnavailable(
+        ILogger logger,
+        Exception exception);
 
     [Inject]
-    private PocketBaseClient PocketBase { get; set; } = default!;
+    private PocketBaseClient PocketBase { get; set; } = null!;
 
     [Inject]
-    private ILogger<FaqsEmbed> Logger { get; set; } = default!;
+    private ILogger<FaqsEmbed> Logger { get; set; } = null!;
+
+    [CascadingParameter]
+    private HttpContext? HttpContext { get; set; }
 
     private IReadOnlyList<Faq> _faqs = [];
 
@@ -21,14 +31,16 @@ public partial class FaqsEmbed
     {
         try
         {
-            // Teaser: the first three questions, with a link to the full hub.
-            var faqs = await PocketBase.GetFaqsAsync();
-            _faqs = [.. faqs.Take(3)];
+            // GetFaqsAsync is ordered by topic, then question, so the first entries
+            // the teaser takes are stable across requests.
+            var faqs = await PocketBase.GetFaqsAsync(HttpContext?.RequestAborted ?? CancellationToken.None);
+            _faqs = [.. faqs.Take(TeaserCount)];
         }
-        catch (HttpRequestException ex)
+        catch (PocketBaseUnavailableException exception)
         {
-            // Source unreachable -> show no teaser instead of a 500.
-            LogLoadFailed(Logger, ex);
+            // Only part of the page fails: omit the teaser, keep the page (and its
+            // 200) intact. A missing teaser is degraded, not broken.
+            LogSourceUnavailable(Logger, exception);
         }
     }
 }

Elternbeirat.Web/Features/Embeds/PostsEmbed.razor

@@ -1,23 +1,18 @@
+@if (_latest.Count > 0)
+{
     <section class="embed embed-posts">
         <h2>Aktuelle Beiträge</h2>
-
-    @if (_latest.Count == 0)
-    {
-        <p>Zurzeit gibt es keine Beiträge.</p>
-    }
-    else
-    {
         <ul class="post-list">
             @foreach (var post in _latest)
             {
                 <li>
                     <a href="@($"/posts/{post.Slug}")">@post.Title</a>
-                    <time datetime="@post.Date.ToString("yyyy-MM-dd")">
-                        @post.Date.ToString("d. MMMM yyyy", German)
+                    <time datetime="@post.Date.ToString("yyyy-MM-dd", CultureInfo.InvariantCulture)">
+                        @post.Date.ToString("d. MMMM yyyy", Cultures.German)
                     </time>
                 </li>
             }
         </ul>
         <p class="embed-more"><a href="/posts">Alle Beiträge <span aria-hidden="true">&rarr;</span></a></p>
-    }
     </section>
+}

Elternbeirat.Web/Features/Embeds/PostsEmbed.razor.cs

@@ -1,4 +1,3 @@
-using System.Globalization;
 using Elternbeirat.Contracts;
 using Elternbeirat.PocketBase;
 using Microsoft.AspNetCore.Components;
@@ -7,16 +6,24 @@ namespace Elternbeirat.Web.Features.Embeds;
 
 public partial class PostsEmbed
 {
-    private static readonly CultureInfo German = CultureInfo.GetCultureInfo("de-DE");
+    // Number of posts shown in the teaser; the full list is one link away.
+    private const int TeaserCount = 3;
 
-    [LoggerMessage(Level = LogLevel.Warning, Message = "Could not load posts for an embed from PocketBase.")]
-    private static partial void LogLoadFailed(ILogger logger, Exception exception);
+    [LoggerMessage(
+        Level = LogLevel.Warning,
+        Message = "Could not load posts for an embed from PocketBase; the teaser is omitted.")]
+    private static partial void LogSourceUnavailable(
+        ILogger logger,
+        Exception exception);
 
     [Inject]
-    private PocketBaseClient PocketBase { get; set; } = default!;
+    private PocketBaseClient PocketBase { get; set; } = null!;
 
     [Inject]
-    private ILogger<PostsEmbed> Logger { get; set; } = default!;
+    private ILogger<PostsEmbed> Logger { get; set; } = null!;
+
+    [CascadingParameter]
+    private HttpContext? HttpContext { get; set; }
 
     private IReadOnlyList<Post> _latest = [];
 
@@ -24,14 +31,15 @@ public partial class PostsEmbed
     {
         try
         {
-            // Teaser: the three most recent posts, with a link to the full list.
-            var posts = await PocketBase.GetPostsAsync();
-            _latest = [.. posts.Take(3)];
+            // GetPostsAsync returns newest first, so the first entries are the latest.
+            var posts = await PocketBase.GetPostsAsync(HttpContext?.RequestAborted ?? CancellationToken.None);
+            _latest = [.. posts.Take(TeaserCount)];
         }
-        catch (HttpRequestException ex)
+        catch (PocketBaseUnavailableException exception)
         {
-            // Source unreachable -> show no teaser instead of a 500.
-            LogLoadFailed(Logger, ex);
+            // Only part of the page fails: omit the teaser, keep the page (and its
+            // 200) intact. A missing teaser is degraded, not broken.
+            LogSourceUnavailable(Logger, exception);
         }
     }
 }

Elternbeirat.Web/Features/Events/EventList.razor

@@ -4,6 +4,12 @@
 
 <h1>Termine</h1>
 
+@if (_unavailable)
+{
+    <p>Die Termine sind gerade nicht erreichbar. Bitte später erneut versuchen.</p>
+}
+else
+{
     <p class="intro">
         Alle Termine des Elternbeirats auf einen Blick. Sie können den Kalender auch
         <a href="/events.ics">abonnieren</a> und in Ihrer Kalender-App automatisch
@@ -54,3 +60,4 @@ else
             }
         </ul>
     }
+}

Elternbeirat.Web/Features/Events/EventList.razor.cs

@@ -1,48 +1,67 @@
 using Elternbeirat.Contracts;
 using Elternbeirat.PocketBase;
+using Elternbeirat.Web.Shared;
 using Microsoft.AspNetCore.Components;
 
 namespace Elternbeirat.Web.Features.Events;
 
 public partial class EventList
 {
-    [LoggerMessage(Level = LogLevel.Warning, Message = "Could not load events from PocketBase.")]
-    private static partial void LogLoadFailed(ILogger logger, Exception exception);
+    [LoggerMessage(
+        Level = LogLevel.Error,
+        Message = "Could not load events from PocketBase; content source is unavailable.")]
+    private static partial void LogSourceUnavailable(
+        ILogger logger,
+        Exception exception);
 
     [Inject]
-    private PocketBaseClient PocketBase { get; set; } = default!;
+    private PocketBaseClient PocketBase { get; set; } = null!;
 
     [Inject]
-    private ILogger<EventList> Logger { get; set; } = default!;
+    private ILogger<EventList> Logger { get; set; } = null!;
+
+    [CascadingParameter]
+    private HttpContext? HttpContext { get; set; }
 
     private IReadOnlyList<Event> _upcoming = [];
     private IReadOnlyList<Event> _past = [];
 
+    // Set when the content source could not be reached or read. The markup then
+    // shows a "temporarily unavailable" note instead of "no events", matching the
+    // 503 this sets on the response.
+    private bool _unavailable;
+
     protected override async Task OnInitializedAsync()
     {
         IReadOnlyList<Event> events;
         try
         {
-            events = await PocketBase.GetEventsAsync();
+            events = await PocketBase.GetEventsAsync(HttpContext?.RequestAborted ?? CancellationToken.None);
         }
-        catch (HttpRequestException ex)
+        catch (PocketBaseUnavailableException exception)
         {
-            // Source unreachable -> show empty sections instead of a 500. The page
-            // stays up; the "keine Termine" note is rendered.
-            LogLoadFailed(Logger, ex);
+            // Empty sections would claim there are no events. The site works, its
+            // data store is down: 503 and an honest note.
+            LogSourceUnavailable(Logger, exception);
+            _unavailable = true;
+            SourceUnavailable.SetStatus(HttpContext);
             return;
         }
 
         // Split into upcoming and past by date, so an event earlier today still
         // counts as upcoming. Upcoming earliest first, past most recent first.
         var today = DateOnly.FromDateTime(DateTime.Today);
-        _upcoming = events
-            .Where(e => DateOnly.FromDateTime(e.Start) >= today)
-            .OrderBy(e => e.Start)
-            .ToList();
-        _past = events
-            .Where(e => DateOnly.FromDateTime(e.Start) < today)
-            .OrderByDescending(e => e.Start)
-            .ToList();
+        _upcoming =
+        [
+            .. events
+                .Where(@event => DateOnly.FromDateTime(@event.Start) >= today)
+                .OrderBy(@event => @event.Start)
+        ];
+        _past =
+        [
+            .. events
+                .Where(@event => DateOnly.FromDateTime(@event.Start) < today)
+                .OrderByDescending(@event => @event.Start)
+        ];
     }
 }

Elternbeirat.Web/Features/Faqs/FaqList.razor

@@ -4,7 +4,11 @@
 
 <h1>Häufige Fragen</h1>
 
-@if (_groups.Count == 0)
+@if (_unavailable)
+{
+    <p>Die Fragen sind gerade nicht erreichbar. Bitte später erneut versuchen.</p>
+}
+else if (_groups.Count == 0)
 {
     <p>Zurzeit gibt es keine Fragen.</p>
 }

Elternbeirat.Web/Features/Faqs/FaqList.razor.cs

@@ -1,13 +1,18 @@
 using Elternbeirat.Contracts;
 using Elternbeirat.PocketBase;
+using Elternbeirat.Web.Shared;
 using Microsoft.AspNetCore.Components;
 
 namespace Elternbeirat.Web.Features.Faqs;
 
 public partial class FaqList
 {
-    [LoggerMessage(Level = LogLevel.Warning, Message = "Could not load FAQs from PocketBase.")]
-    private static partial void LogLoadFailed(ILogger logger, Exception exception);
+    [LoggerMessage(
+        Level = LogLevel.Error,
+        Message = "Could not load FAQs from PocketBase; content source is unavailable.")]
+    private static partial void LogSourceUnavailable(
+        ILogger logger,
+        Exception exception);
 
     // German heading per topic. Unknown topics fall back to the raw key so a new
     // topic in PocketBase still shows up rather than being silently dropped.
@@ -21,28 +26,38 @@ public partial class FaqList
         };
 
     [Inject]
-    private PocketBaseClient PocketBase { get; set; } = default!;
+    private PocketBaseClient PocketBase { get; set; } = null!;
 
     [Inject]
-    private ILogger<FaqList> Logger { get; set; } = default!;
+    private ILogger<FaqList> Logger { get; set; } = null!;
+
+    [CascadingParameter]
+    private HttpContext? HttpContext { get; set; }
 
     private IReadOnlyList<IGrouping<string, Faq>> _groups = [];
 
+    // Set when the content source could not be reached or read. The markup then
+    // shows a "temporarily unavailable" note instead of "no questions", matching
+    // the 503 this sets on the response.
+    private bool _unavailable;
+
     protected override async Task OnInitializedAsync()
     {
         try
         {
-            var faqs = await PocketBase.GetFaqsAsync();
+            var faqs = await PocketBase.GetFaqsAsync(HttpContext?.RequestAborted ?? CancellationToken.None);
             _groups = [.. faqs.GroupBy(faq => faq.Topic)];
         }
-        catch (HttpRequestException ex)
+        catch (PocketBaseUnavailableException exception)
         {
-            // Source unreachable -> show an empty page instead of a 500. The page
-            // stays up; the "keine Fragen" note is rendered.
-            LogLoadFailed(Logger, ex);
+            // An empty page would claim there are no questions. The site works, its
+            // data store is down: 503 and an honest note.
+            LogSourceUnavailable(Logger, exception);
+            _unavailable = true;
+            SourceUnavailable.SetStatus(HttpContext);
         }
     }
 
-    private static string TopicLabel(string topic) =>
-        TopicLabels.TryGetValue(topic, out var label) ? label : topic;
+    private static string TopicLabel(string topic)
+        => TopicLabels.GetValueOrDefault(topic, topic);
 }

Elternbeirat.Web/Features/Home/Home.razor.cs

@@ -8,8 +8,8 @@ public partial class Home
 {
     [LoggerMessage(
         Level = LogLevel.Warning,
-        Message = "Could not load the home page from PocketBase.")]
-    private static partial void LogLoadFailed(
+        Message = "Could not load the home page from PocketBase; embeds are omitted.")]
+    private static partial void LogSourceUnavailable(
         ILogger logger,
         Exception exception);
 
@@ -19,6 +19,9 @@ public partial class Home
     [Inject]
     private ILogger<Home> Logger { get; set; } = null!;
 
+    [CascadingParameter]
+    private HttpContext? HttpContext { get; set; }
+
     // Which dynamic blocks the home page shows is editorial: it comes from the
     // "home" page's embed field in PocketBase, not from hard-coded markup.
     private IReadOnlyList<string> _embed = [];
@@ -27,14 +30,15 @@ public partial class Home
     {
         try
         {
-            var pages = await PocketBase.GetPagesAsync();
+            var pages = await PocketBase.GetPagesAsync(HttpContext?.RequestAborted ?? default);
             var home = pages.FirstOrDefault(page => Page.IsHomeSlug(page.Slug));
             _embed = home?.Embed ?? [];
         }
-        catch (HttpRequestException exception)
+        catch (PocketBaseUnavailableException exception)
         {
-            // Source unreachable -> render the intro without embeds instead of a 500.
-            LogLoadFailed(Logger, exception);
+            // Only the embeds fail: render the static intro without them instead of a
+            // 500. The home page's own text is markup, so it stays intact.
+            LogSourceUnavailable(Logger, exception);
         }
     }
 }

Elternbeirat.Web/Features/Pages/ContentPage.razor

@@ -1,14 +1,18 @@
 @page "/{Slug}"
 
-@if (_page is null)
+@if (_unavailable)
 {
-    <PageTitle>Nicht gefunden</PageTitle>
+    <PageTitle>Vorübergehend nicht erreichbar</PageTitle>
+    <p>Die Seite ist gerade nicht erreichbar. Bitte später erneut versuchen.</p>
 }
-else
+else if (_page is not null)
 {
     <PageTitle>@_page.Title</PageTitle>
     <article>
+        <h1>@_page.Title</h1>
         @Body
     </article>
     <PageEmbeds Embed="_page.Embed" />
 }
+@* No page and not unavailable: the slug was unknown; NavigationManager.NotFound()
+   already ran in OnParametersSetAsync and renders the not-found page. *@

Elternbeirat.Web/Features/Pages/ContentPage.razor.cs

@@ -8,9 +8,9 @@ namespace Elternbeirat.Web.Features.Pages;
 public partial class ContentPage
 {
     [LoggerMessage(
-        Level = LogLevel.Warning,
-        Message = "Could not load page '{slug}' from PocketBase.")]
-    private static partial void LogLoadFailed(
+        Level = LogLevel.Error,
+        Message = "Could not load page '{Slug}' from PocketBase; content source is unavailable.")]
+    private static partial void LogSourceUnavailable(
         ILogger logger,
         string slug,
         Exception exception);
@@ -24,11 +24,19 @@ public partial class ContentPage
     [Inject]
     private ILogger<ContentPage> Logger { get; set; } = null!;
 
+    [Inject]
+    private NavigationManager Navigation { get; set; } = null!;
+
     [CascadingParameter]
     private HttpContext? HttpContext { get; set; }
 
     private Page? _page;
 
+    // Set when the content source could not be reached or read. The markup then
+    // shows a "temporarily unavailable" note instead of a not-found page, matching
+    // the 503 this sets on the response.
+    private bool _unavailable;
+
     // The page body rendered from Markdown to HTML, ready to emit as a
     // MarkupString in the markup.
     private MarkupString Body => (MarkupString)Markdown.ToHtml(_page?.Body);
@@ -37,24 +45,23 @@ public partial class ContentPage
     {
         try
         {
-            var pages = await PocketBase.GetPagesAsync();
+            var pages = await PocketBase.GetPagesAsync(HttpContext?.RequestAborted ?? CancellationToken.None);
             _page = pages.FirstOrDefault(
-                p => string.Equals(p.Slug, Slug, StringComparison.OrdinalIgnoreCase));
+                page => string.Equals(page.Slug, Slug, StringComparison.OrdinalIgnoreCase));
         }
-        catch (HttpRequestException ex)
+        catch (PocketBaseUnavailableException exception)
         {
-            // Source unreachable -> treat as "not found" rather than a 500. The
-            // 404 branch below serves the friendly /not-found page.
-            LogLoadFailed(Logger, Slug, ex);
-            _page = null;
+            // The site works, its data store is down: 503, not 404.
+            LogSourceUnavailable(Logger, Slug, exception);
+            _unavailable = true;
+            SourceUnavailable.SetStatus(HttpContext);
+            return;
         }
 
-        // Unknown slug (or unreachable source) -> 404, so
-        // UseStatusCodePagesWithReExecute serves the /not-found page instead of an
-        // empty 200 response.
-        if (_page is null && HttpContext is not null)
+        if (_page is null)
         {
-            HttpContext.Response.StatusCode = StatusCodes.Status404NotFound;
+            // The source answered, but there is no page with this slug: a genuine 404.
+            Navigation.NotFound();
         }
     }
 }

Elternbeirat.Web/Features/Posts/PostDetail.razor

@@ -1,19 +1,25 @@
 @page "/posts/{Slug}"
 
-@if (_post is null)
+@if (_unavailable)
 {
-    <PageTitle>Nicht gefunden</PageTitle>
+    <PageTitle>Vorübergehend nicht erreichbar</PageTitle>
+    <p>Der Beitrag ist gerade nicht erreichbar. Bitte später erneut versuchen.</p>
 }
-else
+else if (_post is not null)
 {
     <PageTitle>@_post.Title</PageTitle>
-    <article>
-        <p class="post-meta">
+    <nav>
         <a href="/posts">&larr; Alle Beiträge</a>
-            <time datetime="@_post.Date.ToString("yyyy-MM-dd")">
-                @_post.Date.ToString("d. MMMM yyyy", German)
+    </nav>
+    <article>
+        <header>
+            <h1>@_post.Title</h1>
+            <time class="post-meta" datetime="@_post.Date.ToString("yyyy-MM-dd", CultureInfo.InvariantCulture)">
+                @_post.Date.ToString("d. MMMM yyyy", Cultures.German)
             </time>
-        </p>
+        </header>
         @Body
     </article>
 }
+@* No post and not unavailable: the slug was unknown; NavigationManager.NotFound()
+   already ran in OnParametersSetAsync and renders the not-found page. *@

Elternbeirat.Web/Features/Posts/PostDetail.razor.cs

@@ -1,33 +1,42 @@
-using System.Globalization;
 using Elternbeirat.Contracts;
 using Elternbeirat.PocketBase;
 using Elternbeirat.Web.Shared;
 using Microsoft.AspNetCore.Components;
-using Microsoft.AspNetCore.Http;
 
 namespace Elternbeirat.Web.Features.Posts;
 
 public partial class PostDetail
 {
-    private static readonly CultureInfo German = CultureInfo.GetCultureInfo("de-DE");
-
-    [LoggerMessage(Level = LogLevel.Warning, Message = "Could not load post '{slug}' from PocketBase.")]
-    private static partial void LogLoadFailed(ILogger logger, string slug, Exception exception);
+    [LoggerMessage(
+        Level = LogLevel.Error,
+        Message = "Could not load post '{Slug}' from PocketBase; content source is unavailable.")]
+    private static partial void LogSourceUnavailable(
+        ILogger logger,
+        string slug,
+        Exception exception);
 
     [Parameter]
     public string Slug { get; set; } = string.Empty;
 
     [Inject]
-    private PocketBaseClient PocketBase { get; set; } = default!;
+    private PocketBaseClient PocketBase { get; set; } = null!;
 
     [Inject]
-    private ILogger<PostDetail> Logger { get; set; } = default!;
+    private ILogger<PostDetail> Logger { get; set; } = null!;
+
+    [Inject]
+    private NavigationManager Navigation { get; set; } = null!;
 
     [CascadingParameter]
     private HttpContext? HttpContext { get; set; }
 
     private Post? _post;
 
+    // Set when the content source could not be reached or read. The markup then
+    // shows a "temporarily unavailable" note instead of a not-found page, matching
+    // the 503 this sets on the response.
+    private bool _unavailable;
+
     // The post body rendered from Markdown to HTML, ready to emit as a
     // MarkupString in the markup.
     private MarkupString Body => (MarkupString)Markdown.ToHtml(_post?.Body);
@@ -36,24 +45,23 @@ public partial class PostDetail
     {
         try
         {
-            var posts = await PocketBase.GetPostsAsync();
+            var posts = await PocketBase.GetPostsAsync(HttpContext?.RequestAborted ?? CancellationToken.None);
             _post = posts.FirstOrDefault(
-                p => string.Equals(p.Slug, Slug, StringComparison.OrdinalIgnoreCase));
+                post => string.Equals(post.Slug, Slug, StringComparison.OrdinalIgnoreCase));
         }
-        catch (HttpRequestException ex)
+        catch (PocketBaseUnavailableException exception)
         {
-            // Source unreachable -> treat as "not found" rather than a 500. The
-            // 404 branch below serves the friendly /not-found page.
-            LogLoadFailed(Logger, Slug, ex);
-            _post = null;
+            // The site works, its data store is down: 503, not 404.
+            LogSourceUnavailable(Logger, Slug, exception);
+            _unavailable = true;
+            SourceUnavailable.SetStatus(HttpContext);
+            return;
         }
 
-        // Unknown slug (or unreachable source) -> 404, so
-        // UseStatusCodePagesWithReExecute serves the /not-found page instead of an
-        // empty 200 response.
-        if (_post is null && HttpContext is not null)
+        if (_post is null)
         {
-            HttpContext.Response.StatusCode = StatusCodes.Status404NotFound;
+            // The source answered, but there is no post with this slug: a genuine 404.
+            Navigation.NotFound();
         }
     }
 }

Elternbeirat.Web/Features/Posts/PostList.razor

@@ -4,7 +4,11 @@
 
 <h1>Beiträge</h1>
 
-@if (_posts.Count == 0)
+@if (_unavailable)
+{
+    <p>Die Beiträge sind gerade nicht erreichbar. Bitte später erneut versuchen.</p>
+}
+else if (_posts.Count == 0)
 {
     <p>Zurzeit gibt es keine Beiträge.</p>
 }
@@ -15,8 +19,8 @@ else
         {
             <li>
                 <a href="@($"/posts/{post.Slug}")">@post.Title</a>
-                <time datetime="@post.Date.ToString("yyyy-MM-dd")">
-                    @post.Date.ToString("d. MMMM yyyy", German)
+                <time datetime="@post.Date.ToString("yyyy-MM-dd", CultureInfo.InvariantCulture)">
+                    @post.Date.ToString("d. MMMM yyyy", Cultures.German)
                 </time>
             </li>
         }

Elternbeirat.Web/Features/Posts/PostList.razor.cs

@@ -1,36 +1,48 @@
-using System.Globalization;
 using Elternbeirat.Contracts;
 using Elternbeirat.PocketBase;
+using Elternbeirat.Web.Shared;
 using Microsoft.AspNetCore.Components;
 
 namespace Elternbeirat.Web.Features.Posts;
 
 public partial class PostList
 {
-    [LoggerMessage(Level = LogLevel.Warning, Message = "Could not load posts from PocketBase.")]
-    private static partial void LogLoadFailed(ILogger logger, Exception exception);
-
-    private static readonly CultureInfo German = CultureInfo.GetCultureInfo("de-DE");
+    [LoggerMessage(
+        Level = LogLevel.Error,
+        Message = "Could not load posts from PocketBase; content source is unavailable.")]
+    private static partial void LogSourceUnavailable(
+        ILogger logger,
+        Exception exception);
 
     [Inject]
-    private PocketBaseClient PocketBase { get; set; } = default!;
+    private PocketBaseClient PocketBase { get; set; } = null!;
 
     [Inject]
-    private ILogger<PostList> Logger { get; set; } = default!;
+    private ILogger<PostList> Logger { get; set; } = null!;
+
+    [CascadingParameter]
+    private HttpContext? HttpContext { get; set; }
 
     private IReadOnlyList<Post> _posts = [];
 
+    // Set when the content source could not be reached or read. The markup then
+    // shows a "temporarily unavailable" note instead of "no posts", matching the
+    // 503 this sets on the response.
+    private bool _unavailable;
+
     protected override async Task OnInitializedAsync()
     {
         try
         {
-            _posts = await PocketBase.GetPostsAsync();
+            _posts = await PocketBase.GetPostsAsync(HttpContext?.RequestAborted ?? CancellationToken.None);
         }
-        catch (HttpRequestException ex)
+        catch (PocketBaseUnavailableException exception)
         {
-            // Source unreachable -> show an empty list instead of a 500. The page
-            // stays up; the "keine Beiträge" note is rendered.
-            LogLoadFailed(Logger, ex);
+            // An empty list would claim there are no posts. The site works, its
+            // data store is down: 503 and an honest note.
+            LogSourceUnavailable(Logger, exception);
+            _unavailable = true;
+            SourceUnavailable.SetStatus(HttpContext);
         }
     }
 }

Elternbeirat.Web/Program.cs

@@ -24,23 +24,26 @@ var app = builder.Build();
 // as HTTP and with the proxy IP instead of the client IP.
 // KnownNetworks/KnownProxies are deliberately empty because only NPM reaches
 // the container.
-app.UseForwardedHeaders(new ForwardedHeadersOptions
+app.UseForwardedHeaders(
+    new ForwardedHeadersOptions
     {
-    ForwardedHeaders = ForwardedHeaders.XForwardedFor | ForwardedHeaders.XForwardedProto,
-    KnownIPNetworks = { },
-    KnownProxies = { }
+        ForwardedHeaders = ForwardedHeaders.XForwardedFor | ForwardedHeaders.XForwardedProto
     });
 
 // Configure the HTTP request pipeline.
-if (!app.Environment.IsDevelopment())
+if (app.Environment.IsDevelopment() is false)
 {
     app.UseExceptionHandler("/Error", createScopeForErrors: true);
     // No UseHsts() and no UseHttpsRedirection(): NPM sets HSTS and terminates
     // TLS. Both here would create a redirect loop behind the proxy.
 }
 
-app.UseStatusCodePagesWithReExecute("/not-found", createScopeForStatusCodePages: true);
-
+// No UseStatusCodePagesWithReExecute: the Router renders the NotFoundPage
+// (Pages.NotFound) in process for both an unmatched route and an explicit
+// NavigationManager.NotFound() from a component (see Routes.razor). Re-executing
+// every error code to /not-found would also turn a 503 (content source down) into
+// a "not found" page; leaving it out lets those components keep their own
+// "temporarily unavailable" markup and 503 status.
 app.UseAntiforgery();
 
 app.MapStaticAssets();
@@ -49,14 +52,14 @@ app.MapRazorComponents<App>();
 // Subscribable calendar feed of all events. A minimal API endpoint rather than
 // a Razor page because it returns text/calendar, not HTML. Reads from PocketBase
 // per request; an unreachable source yields an empty calendar, not a 500.
-app.MapGet("/events.ics", async (PocketBaseClient pocketBase) =>
+app.MapGet("/events.ics", async (PocketBaseClient pocketBase, CancellationToken token) =>
 {
     IReadOnlyList<Event> events;
     try
     {
-        events = await pocketBase.GetEventsAsync();
+        events = await pocketBase.GetEventsAsync(token);
     }
-    catch (HttpRequestException)
+    catch (PocketBaseUnavailableException)
     {
         events = [];
     }

Elternbeirat.Web/Shared/Cultures.cs

@@ -0,0 +1,21 @@
+using System.Globalization;
+
+namespace Elternbeirat.Web.Shared;
+
+/// <summary>
+///     Shared <see cref="CultureInfo"/> instances used to format visitor-facing
+///     text.
+/// </summary>
+/// <remarks>
+///     Kept in one place so every component renders month and weekday names the
+///     same way, rather than each holding its own <c>de-DE</c> lookup. This is only
+///     for display text; machine-readable output (e.g. an HTML <c>datetime</c>
+///     attribute) uses <see cref="CultureInfo.InvariantCulture"/> instead.
+/// </remarks>
+internal static class Cultures
+{
+    /// <summary>
+    ///     German culture, for the month and weekday names visitors read.
+    /// </summary>
+    public static readonly CultureInfo German = CultureInfo.GetCultureInfo("de-DE");
+}

Elternbeirat.Web/Shared/EventFormat.cs

@@ -1,4 +1,3 @@
-using System.Globalization;
 using Elternbeirat.Contracts;
 
 namespace Elternbeirat.Web.Shared;
@@ -22,11 +21,6 @@ public static class EventFormat
     /// </summary>
     private const string ShortDate = "d. MMMM yyyy";
 
-    /// <summary>
-    ///     The culture used for month and weekday names.
-    /// </summary>
-    private static readonly CultureInfo German = CultureInfo.GetCultureInfo("de-DE");
-
     /// <summary>
     ///     Formats the date range of an event.
     /// </summary>
@@ -54,7 +48,7 @@ public static class EventFormat
             (var start, null, var hasTime)
                 => Stamp(start, LongDate, hasTime),
             (var start, { } end, true) when end.Date == start.Date
-                => $"{start.ToString(LongDate, German)}, {start.ToString("HH:mm", German)}–{end.ToString("HH:mm", German)} Uhr",
+                => $"{start.ToString(LongDate, Cultures.German)}, {start.ToString("HH:mm", Cultures.German)}–{end.ToString("HH:mm", Cultures.German)} Uhr",
             (var start, { } end, false) when end.Date == start.Date
                 => Stamp(start, LongDate, withTime: false),
             (var start, { } end, var hasTime)
@@ -78,6 +72,6 @@ public static class EventFormat
     /// </returns>
     private static string Stamp(DateTime value, string dateFormat, bool withTime)
         => withTime
-            ? value.ToString(dateFormat + ", HH:mm", German) + " Uhr"
-            : value.ToString(dateFormat, German);
+            ? value.ToString(dateFormat + ", HH:mm", Cultures.German) + " Uhr"
+            : value.ToString(dateFormat, Cultures.German);
 }

Elternbeirat.Web/Shared/SourceUnavailable.cs

@@ -0,0 +1,30 @@
+namespace Elternbeirat.Web.Shared;
+
+/// <summary>
+///     Marks the current response as HTTP 503 when the content source is down.
+/// </summary>
+/// <remarks>
+///     Several components handle a <see cref="PocketBase.PocketBaseUnavailableException"/>
+///     the same way: the site works but PocketBase does not, so the response is a
+///     503 and the component renders a "temporarily unavailable" note instead of
+///     empty content that would read as 200 "there is nothing here". This puts the
+///     status-setting in one place so those components do not each repeat it.
+/// </remarks>
+internal static class SourceUnavailable
+{
+    /// <summary>
+    ///     Sets the response status to 503 Service Unavailable, if there is a
+    ///     response to set it on.
+    /// </summary>
+    /// <param name="context">
+    ///     The current HTTP context, or <see langword="null"/> when the component
+    ///     renders outside a request (in which case there is nothing to do).
+    /// </param>
+    public static void SetStatus(HttpContext? context)
+    {
+        if (context is not null)
+        {
+            context.Response.StatusCode = StatusCodes.Status503ServiceUnavailable;
+        }
+    }
+}

Elternbeirat.Web/_Imports.razor

@@ -1,3 +1,4 @@
+@using System.Globalization
 @using System.Net.Http
 @using System.Net.Http.Json
 @using Microsoft.AspNetCore.Components.Forms