Add scrape/ingestion engine + validation, and 24h shift hour-range visualization

Scrape engine (Services/Scraping/): pluggable IListingSource (working sample + Telegram/Divar credential-ready stubs) → IngestionService (content-hash dedupe → parse → validate → review queue) → ListingValidator (completeness score + spam screen) → IngestionWorker (config-gated hosted service). RawListing gains ContentHash/Confidence/ValidationNotes; RawListingStatus.Flagged. Admin /Admin gets run-now, source list, confidence + flagged queue.

Hour-range viz: _HourBar 24h timeline bar (colored by type, overnight wrap) on shift cards, recommendation cards, and detail.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

src/JobsMedical.Web/Services/Scraping/IListingSource.cs

@@ -0,0 +1,15 @@
+namespace JobsMedical.Web.Services.Scraping;
+
+/// <summary>One raw post pulled from a source (a Telegram message, a Divar ad, etc.).</summary>
+public record ScrapedItem(string Source, string RawText, string? SourceUrl = null);
+
+/// <summary>
+/// A pluggable source the ingestion engine pulls from. Implement once per channel/site.
+/// `Enabled` lets a source be present but dormant until it's configured with credentials.
+/// </summary>
+public interface IListingSource
+{
+    string Name { get; }
+    bool Enabled { get; }
+    Task<IReadOnlyList<ScrapedItem>> FetchAsync(CancellationToken ct = default);
+}