docs: remove C# Implementation Considerations sections, clean up temp scripts, reorganize test files

- Remove 'C# Implementation Considerations' sections from 34 indicator .md files
- Delete 29 temp PowerShell scripts (_fix_mojibake.ps1, _hex_scan.ps1, etc.)
- Move test files into tests/ subdirectories for consistent project structure
- Add trader-focused bullet points to indicator documentation

lib/trends_IIR/dema/Dema.md

@@ -216,106 +216,6 @@ var dema = new Dema(source, period);
 | **Tulip** | ✅ | Matches `dema` (tolerance: 1e-9) |
 | **Ooples** | ✅ | Matches `2*EMA - EMA(EMA)` formula |
 
-## C# Implementation Considerations
-
-QuanTAlib's DEMA uses cascaded EMA instances with bias compensation and extensive FMA optimization. The implementation demonstrates several high-performance patterns:
-
-### State Management
-
-```csharp
-[StructLayout(LayoutKind.Auto)]
-private record struct EmaState(double Ema, double E, bool IsHot, bool IsCompensated)
-{
-    public static EmaState New() => new() { Ema = 0, E = 1.0, IsHot = false, IsCompensated = false };
-}
-
-private EmaState _state1 = EmaState.New();
-private EmaState _state2 = EmaState.New();
-private EmaState _p_state1 = EmaState.New();  // Bar correction backup
-private EmaState _p_state2 = EmaState.New();  // Bar correction backup
-```
-
-Each EMA stage has its own state with bias compensation tracking. Four state copies enable bar correction across both stages.
-
-### Key Optimizations
-
-| Technique | Implementation | Benefit |
-| :--- | :--- | :--- |
-| **Precomputed constants** | `_alpha = 2.0/(period+1)`, `_decay = 1-_alpha` | Eliminates division in hot path |
-| **FMA in EMA update** | `FusedMultiplyAdd(ema, decay, alpha * input)` | Hardware-accelerated smoothing |
-| **FMA in combiner** | `FusedMultiplyAdd(2.0, e1, -e2)` | Single instruction for DEMA formula |
-| **Bias compensation** | Tracks convergence factor `E` | Accurate warmup values |
-| **Auto-transition** | `IsCompensated` flag skips division | Steady-state optimization |
-
-### FMA Usage
-
-```csharp
-// EMA smoothing step (IIR pattern)
-state.Ema = Math.FusedMultiplyAdd(state.Ema, decay, alpha * input);
-
-// Final DEMA combiner: 2*e1 - e2 → FMA(2.0, e1, -e2)
-double result = Math.FusedMultiplyAdd(2.0, e1, -e2);
-```
-
-### Bias Compensation Logic
-
-```csharp
-[MethodImpl(MethodImplOptions.AggressiveInlining | MethodImplOptions.AggressiveOptimization)]
-private static double Compute(double input, double alpha, double decay, ref EmaState state)
-{
-    state.Ema = Math.FusedMultiplyAdd(state.Ema, decay, alpha * input);
-
-    if (!state.IsCompensated)
-    {
-        state.E *= decay;  // Bias factor decays each tick
-
-        if (!state.IsHot && state.E <= 0.05)  // 95% coverage
-            state.IsHot = true;
-
-        if (state.E <= 1e-10)  // Full convergence
-        {
-            state.IsCompensated = true;
-            return state.Ema;
-        }
-        return state.Ema / (1.0 - state.E);  // Bias-corrected
-    }
-    return state.Ema;  // No compensation needed
-}
-```
-
-### Memory Layout
-
-| Field | Type | Size | Purpose |
-| :--- | :--- | :---: | :--- |
-| `_alpha` | double | 8 bytes | EMA smoothing factor |
-| `_decay` | double | 8 bytes | 1 - alpha (precomputed) |
-| `_state1` | EmaState | 20 bytes | First EMA stage state |
-| `_state2` | EmaState | 20 bytes | Second EMA stage state |
-| `_p_state1` | EmaState | 20 bytes | Bar correction backup |
-| `_p_state2` | EmaState | 20 bytes | Bar correction backup |
-| `_lastValidValue` | double | 8 bytes | NaN substitution |
-| `_p_lastValidValue` | double | 8 bytes | Bar correction backup |
-| **Instance total** | | **~112 bytes** | No period-dependent allocations |
-
-### Bar Correction Pattern
-
-```csharp
-if (isNew)
-{
-    _p_state1 = _state1;
-    _p_state2 = _state2;
-    _p_lastValidValue = _lastValidValue;
-}
-else
-{
-    _state1 = _p_state1;
-    _state2 = _p_state2;
-    _lastValidValue = _p_lastValidValue;
-}
-```
-
-Both EMA states are rolled back atomically for consistent correction.
-
 ## Reference Calculation Table
 
 | Period | Price Sequence | EMA₁ | EMA₂ | DEMA | Notes |