[Alts] Server-side search controls, IP counts, adjustable window

Plumbs the match-type chips through to the server: include_email/include_clientid/include_ip skip disabled identifier types in both matching and frontier expansion, so excluded types (e.g. throwaway domains) never enter the graph at any depth. Session lookback becomes adjustable (session_months, clamped 1-24, default 6). Each alt row carries ip_count, the distinct recent session IP count shown in a new IPs column. All proto additions are optional with old defaults, so old clients/servers interoperate.

libcockatrice_protocol/libcockatrice/protocol/pb/moderator_commands.proto

@@ -170,6 +170,10 @@ message Command_GetUserAlts {
     }
     optional string user_name = 1;
     optional uint32 depth = 2 [default = 1]; // BFS depth: 1 = direct matches only, up to 3 for transitive alts-of-alts
+    optional bool include_email = 3 [default = true];    // match and expand over registration email
+    optional bool include_clientid = 4 [default = true]; // match and expand over current and historic client ids
+    optional bool include_ip = 5 [default = true];       // match and expand over recent session IPs
+    optional uint32 session_months = 6 [default = 6];    // session lookback window in months, 1-24
 }
 
 message Command_GetModeratorLastLogins {