Add /inspect command to view player equipment

- Add CMSG_INSPECT (0x114) and SMSG_INSPECT_RESULTS (0x115) opcodes
- Implement InspectPacket builder for sending inspect requests
- Add inspectTarget() method to GameHandler with validation
- Add /inspect slash command in chat system
- Validate target is a player before sending inspect request
- Show helpful error messages for invalid inspect attempts
- Display confirmation message when inspect request is sent

include/game/game_handler.hpp

@@ -202,6 +202,9 @@ public:
     bool hasTarget() const { return targetGuid != 0; }
     void tabTarget(float playerX, float playerY, float playerZ);
 
+    // Inspection
+    void inspectTarget();
+
     // ---- Phase 1: Name queries ----
     void queryPlayerName(uint64_t guid);
     void queryCreatureInfo(uint32_t entry, uint64_t guid);