This question is probably too broad for the format here and might be closed as such. But it becomes a little unwieldy to place links to even a few of the many existing questions/answers we have here that touch on the various questions you raise in comments. This isn't really so much a complete answer as it is an attempt to point you in a direction where these subjects have already been addressed here.

Is tone mapping automatically applied to RAW images?

A lot of processing is applied to the raw image data collected by the camera's sensor and digitized by the camera's processor before there is what we consider a "viewable image." This processing include what you refer to as "tone mapping."

What do I actually see when I look at the preview from my Camera or LR? Where is the extra range? is it clipped? or already tone mapped?

For more about what a raw file is and what a raw file isn't (Hint: the image you see on your camera's LCD screen or on your computer is not an unprocessed raw image), please see:

RAW files store 3 colors per pixel, or only one?
What does an unprocessed RAW file look like?
Is the Preview file always the photo taken by the camera?
If I save as RAW+JPG, which of the two is shown on the screen of a Canon 600D?
Why are my RAW images already in colour if debayering is not done yet?

What happens when I slide the shadows slider up or the highlights down? what is LR doing to "bring back the highlights"?

What you are looking at on your screen is only one of countless possible interpretations of the raw image data. This preview is based on the instructions that have been given to Lightroom as to how the raw image data should be interpreted. When you move a slider, you change the set of instructions with regard to whatever the slider you moved controls. Lightroom then either:

• Estimates the effect this change would have on reprocessing the raw data with the modified instruction set and renders this change on your screen

or

• Reprocesses the raw image data with the new instruction set and displays the result on your screen.

Which one LR does is determined by your user settings regarding "quality" and "speed' in the 'User preferences' section covering rendering of the preview you see on your screen when working with raw files. In either case, when you actually tell LR to export the file, it will use the instruction set you have designated to go back and reprocess the raw image data to produce a jpeg, png, tiff, etc. for export.

For more about what happens when you move a slider while processing a raw image file in Lightroom or other raw processing applications, please see:

Camera dynamic range and Lightroom exposure slide
Why can software correct white balance more accurately for RAW files than it can with JPEGs?

Are the occasional Halos on RAW caused by the tone mapping?

In short: Yes, halos can be a result of global tone-mapping, whether done via an "HDR" application or by aggressively tone-mapping a single raw file.

Regarding how global tone-mapping can lead to halos in boundary areas between very light and very dark areas, please see:

What is the difference between Digital Blending & HDR technique