Per-character log directories with session continuation and chat log redirect

Organize combat/raw/chat logs into Logs\<realm>\<char>\ directories.
Lazy path setup on first InitializeLogBuffer call resolves character
and realm names, creates directory tree, and reuses files modified
within 30 minutes for session continuation. Chat log added to the
redirection system. Session marker now includes realm name.

Paths not yet redirected before login — needs earlier hook point.

src/combatlog/offsets.zig

@@ -9,10 +9,24 @@
 /// Overwriting the u32 at this address redirects where the combat log file is created.
 pub const COMBAT_LOG_PATH_PTR: usize = 0x00843610;
 
+/// Chat log path pointer — .data section (RW), points to "Logs\WoWChatLog.txt" string.
+/// Index 0 in the path table at 0x0084360c.
+pub const CHAT_LOG_PATH_PTR: usize = 0x0084360c;
+
 /// Runtime combat log buffer handle (log_handles[1], BSS).
 /// Non-zero when combat logging is active. Read to check if we can write log lines.
 pub const COMBAT_LOG_HANDLE: usize = 0x00b50544;
 
+/// Runtime chat log buffer handle (log_handles[0], BSS).
+pub const CHAT_LOG_HANDLE: usize = 0x00b50540;
+
+// =============================================================================
+// Realm name
+// =============================================================================
+
+/// CVar base pointer for realm name. Dereference once, then read string at +0x20.
+pub const REALM_NAME_CVAR_BASE: usize = 0x00c28130;
+
 // =============================================================================
 // Log writing
 // =============================================================================