Add optional name history migration for sa_players_ips

SimpleAdmin upserts sa_players_ips on (steamid, address), so a rename on
the same IP overwrites the old name. sql/players-ips-name-history.sql adds
name to the primary key (binary collation, NOT NULL), so every name a
SteamID joins with is kept and shows on its player page and in name
search. SimpleAdmin's IP cache keeps only the newest row per IP, so its
multi-account and IP-ban checks are unchanged. The file includes a revert.

sql/players-ips-name-history.sql

@@ -0,0 +1,30 @@
+-- Keep every name a SteamID has used, instead of overwriting it.
+--
+-- CS2-SimpleAdmin records each connect with an upsert keyed on sa_players_ips' primary key,
+-- (steamid, address), so a player who rejoins from the same IP under a new name overwrites the old
+-- name. With name in the key, a new name on the same SteamID+IP is a new row; the same name again
+-- still just bumps used_at. SimpleAdmin's own code is unchanged: its IP cache already keeps only
+-- the newest row per IP, so multi-account and IP-ban checks behave as before.
+--
+-- name becomes binary-collated so a case-only rename ("astra" -> "Astra") is also kept, and NOT
+-- NULL because primary key columns can't be NULL (SimpleAdmin always writes a name).
+--
+-- Only records names at connect, like before: a rename mid-session shows up on the next join.
+-- Re-check after upgrading SimpleAdmin, in case a later migration rebuilds this table's key.
+
+UPDATE sa_players_ips SET name = '' WHERE name IS NULL;
+
+ALTER TABLE sa_players_ips
+    MODIFY name VARCHAR(64) CHARACTER SET utf8mb4 COLLATE utf8mb4_bin NOT NULL DEFAULT '',
+    DROP PRIMARY KEY,
+    ADD PRIMARY KEY (steamid, address, name);
+
+-- Revert (drops the older names, keeping the newest row per SteamID+IP):
+--
+-- DELETE a FROM sa_players_ips a JOIN sa_players_ips b
+--     ON a.steamid = b.steamid AND a.address = b.address
+--    AND (a.used_at < b.used_at OR (a.used_at = b.used_at AND a.name < b.name));
+-- ALTER TABLE sa_players_ips
+--     DROP PRIMARY KEY,
+--     ADD PRIMARY KEY (steamid, address),
+--     MODIFY name VARCHAR(64) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL;