lib_murrey

Murrey Math level calculation and overbought/oversold zone detection.

Computes the 8 Murrey Math levels (0/8 through 8/8) plus extended levels (+1/8, -1/8). Returns the current zone (-2 to +2) indicating oversold, neutral, or overbought conditions. Configurable frame size and multiplier.

Ported from Murrey Math Lines by Nanda86:

**Exports:** `get_murrey_levels()` — returns key Murrey levels (0/8, 4/8, 8/8, +1/8, -1/8), zone value, and increment.

Used by: TCD - Trade Consistent & Disciplined (indicator)