Feat: adapt cagire to doux v0.0.12

docs/engine/filters.md

@@ -57,29 +57,15 @@ The `ftype` parameter sets the filter slope (rolloff steepness).
 saw 800 lpf 3 ftype .        ( 48 dB/oct lowpass )
 ```
 
-## Filter Envelope
+## Filter Envelope Modulation
 
-Filters can be modulated by an ADSR envelope. The envelope multiplies the base cutoff:
-
-```
-final_cutoff = lpf + (lpe × envelope × lpf)
-```
-
-When the envelope is at 1.0 and `lpe` is 1.0, the cutoff doubles. When the envelope is at 0, the cutoff equals `lpf`.
+Use the `env` word to apply a DAHDSR envelope to any filter cutoff:
 
 ```forth
-saw 200 lpf 2 lpe 0.01 lpa 0.3 lpd .   ( cutoff sweeps from 600 Hz down to 200 Hz )
+saw 200 8000 0.01 0.3 0.5 0.3 env lpf .   ( cutoff sweeps from 200 to 8000 Hz )
 ```
 
-| Parameter | Description |
-|-----------|-------------|
-| `lpe` | Envelope depth (multiplier, 1.0 = double cutoff at peak) |
-| `lpa` | Attack time in seconds |
-| `lpd` | Decay time in seconds |
-| `lps` | Sustain level (0-1) |
-| `lpr` | Release time in seconds |
-
-The same pattern works for highpass (`hpe`, `hpa`, etc.) and bandpass (`bpe`, `bpa`, etc.).
+The same works for highpass and bandpass: `env hpf`, `env bpf`.
 
 ## Ladder Filters
 
@@ -100,7 +86,7 @@ saw 1000 lbpf 0.8 lbpq .     ( ladder bandpass )
 | `lbpf` | Hz | Ladder bandpass cutoff |
 | `lbpq` | 0-1 | Ladder bandpass resonance |
 
-Ladder filters share the lowpass envelope parameters (`lpe`, `lpa`, etc.).
+Ladder filter cutoffs can also be modulated with `env`, `lfo`, `slide`, etc.
 
 ## EQ