feat(missions): MissionProgressService — counter upsert + achievement claimable on threshold

Also wires IMissionCatalogRepository + IViewerMissionRepository +
IMissionProgressService into DI. Task 17's separate DI step is now
subsumed by these registrations.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

SVSim.EmulatedEntrypoint/Services/IMissionProgressService.cs

@@ -0,0 +1,17 @@
+namespace SVSim.EmulatedEntrypoint.Services;
+
+/// <summary>
+/// Single primitive for "something happened that mission/achievement progress should react to."
+/// Emitters at battle/story finish call this with the FULL list of event keys their event matches
+/// at all granularity levels (broad → narrow). Service does dumb exact-match against catalog.
+/// </summary>
+public interface IMissionProgressService
+{
+    /// <param name="viewerId">Viewer the event applies to.</param>
+    /// <param name="eventKeys">Broad-to-narrow keys. Example: a swordcraft ranked win
+    /// passes ["ranked_win", "ranked_win:swordcraft"]. The order doesn't matter for counter
+    /// increments (each key gets its own counter) but the order is the conventional one used
+    /// by emitters for readability.</param>
+    /// <param name="delta">Count delta per key (default 1).</param>
+    Task RecordEventAsync(long viewerId, IReadOnlyList<string> eventKeys, int delta = 1, CancellationToken ct = default);
+}