Add piano release/brightness controls and instrument hotkeys

docs/controls.md

@@ -76,6 +76,7 @@ Applies to effect select, user/item list modes, item selection, item property li
 
 ## Piano Use Mode
 
+- `1-9`: Switch instrument preset quickly
 - `A S D F G H J K L ; '`: Play white keys (C major from C4 upward)
 - `W E T Y U O P ]`: Play sharps
 - Multiple keys can be held/played at once

docs/item-schema.md

@@ -165,6 +165,8 @@
   "instrument": "piano",
   "attack": 15,
   "decay": 45,
+  "release": 35,
+  "brightness": 55,
   "emitRange": 15
 }
 ```
@@ -174,6 +176,8 @@
 - Selecting a new instrument resets `attack`/`decay` to that instrument's defaults.
 - `attack`: integer, range `0-100`, default `15`.
 - `decay`: integer, range `0-100`, default `45`.
+- `release`: integer, range `0-100`, default `35`.
+- `brightness`: integer, range `0-100`, default `55`.
 - `emitRange`: integer, range `5-20`, default `15`.
 
 ## Packet Shapes

docs/item-types.md

@@ -159,6 +159,8 @@ This is behavior-focused documentation for item types and their defaults.
   - `instrument="piano"`
   - `attack=15`
   - `decay=45`
+  - `release=35`
+  - `brightness=55`
   - `emitRange=15`
 - Global:
   - `useSound=none`
@@ -174,8 +176,10 @@ This is behavior-focused documentation for item types and their defaults.
 - `instrument`: `piano | electric_piano | guitar | organ | bass | violin | synth_lead | nintendo | drum_kit`
 - `attack`: integer `0..100`
 - `decay`: integer `0..100`
+- `release`: integer `0..100`
+- `brightness`: integer `0..100`
 - `emitRange`: integer `5..20`
-- Instrument changes reset `attack`/`decay` to instrument defaults.
+- Instrument changes reset `attack`/`decay`/`release`/`brightness` to instrument defaults.
 
 ## Adding A New Item Type (Registry V1)