feat(web): add public master profiles

Add sanitized public GM profiles with publication controls, public /gm/{slug} pages, and links from public game surfaces.

Bump version -> 3.5.0

src/GmRelay.Web/Services/ISessionStore.cs

@@ -42,12 +42,35 @@ public sealed record WebPublicSession(
     string Status,
     int? MaxPlayers,
     int ActivePlayerCount,
-    int WaitlistedPlayerCount);
+    int WaitlistedPlayerCount,
+    string? MasterProfileSlug = null,
+    string? MasterDisplayName = null);
 
 public sealed record WebPublicClub(
     Guid GroupId,
     string Name,
     string Slug,
+    IReadOnlyList<WebPublicSession> Sessions,
+    string? MasterProfileSlug = null,
+    string? MasterDisplayName = null);
+
+public sealed record MasterProfileSettings(
+    Guid PlayerId,
+    string DisplayName,
+    string? PublicSlug,
+    bool IsPublic,
+    string? Bio);
+
+public sealed record PublicMasterClub(
+    Guid GroupId,
+    string Name,
+    string Slug);
+
+public sealed record PublicMasterProfile(
+    string Slug,
+    string DisplayName,
+    string? Bio,
+    IReadOnlyList<PublicMasterClub> Clubs,
     IReadOnlyList<WebPublicSession> Sessions);
 
 public interface ISessionStore
@@ -85,6 +108,9 @@ public interface ISessionStore
     Task LogSessionChangeAsync(Guid sessionId, string actorExternalUserId, string actorName, string changeType, string? oldValue, string? newValue);
     Task<List<SessionAuditLogEntry>> GetSessionHistoryAsync(Guid sessionId);
     Task UpsertDiscordUserAsync(string discordId, string displayName, string? avatarUrl);
+    Task<MasterProfileSettings?> GetMasterProfileSettingsAsync(string platform, string externalUserId);
+    Task UpdateMasterProfileSettingsAsync(string platform, string externalUserId, string? publicSlug, bool isPublic, string displayName, string? bio);
+    Task<PublicMasterProfile?> GetPublicMasterProfileBySlugAsync(string slug);
 
     // --- Identity linking (issue #35) ---
     Task<Guid?> ResolveEffectivePlayerIdAsync(string platform, string externalUserId);