feat(matching): IBotRoster + hardcoded BotRoster fixture (8 bots, one per class)

AIBotProfile carries the cosmetic metadata the AI rank-battle start
endpoint composes into oppo_info. BotRoster.Pick is deterministic per
MatchContext so mid-flight retries get the same opponent. ai_id values
4001..4008 are placeholders per the existing ai-start.md TODO — we have
no live capture of the prod catalog.

Future improvement: migrate Roster to a bot-roster.json seed under
SVSim.Bootstrap/Data/seeds/ for editability without rebuilds.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

SVSim.EmulatedEntrypoint/Matching/AIBotProfile.cs

@@ -0,0 +1,23 @@
+namespace SVSim.EmulatedEntrypoint.Matching;
+
+/// <summary>
+/// Cosmetic + identity metadata for an AI opponent. Used to compose
+/// <c>oppo_info</c> in the <c>/ai_&lt;fmt&gt;_rank_battle/start</c> response.
+/// The wire keys are camelCase (sleeveId, emblemId, etc.) — the DTO handles
+/// the JSON serialization; this record is the internal-facing shape.
+/// </summary>
+public sealed record AIBotProfile(
+    int AiId,
+    string CountryCode,
+    string UserName,
+    int SleeveId,
+    int EmblemId,
+    int DegreeId,
+    int FieldId,
+    int IsOfficial,
+    int ClassId,
+    int CharaId,
+    int Rank,
+    int BattlePoint,
+    int IsMasterRank,
+    int MasterPoint);