Extend audio graph with new methods

[waynemwashuma]

Objective

Extends the AudioGraph resource to support dynamic updates and safer lifecycle management of audio nodes. It introduces a new update method, a get accessor, and a stricter node typing system to improve flexibility and maintainability of the audio graph.

Solution

• Introduced AudioGraphNode type to distinguish between different audio node types and thier variants.
• Updated the internal graph to store AudioGraphNode instead of raw AudioNode.
  Added the new methods:
• get: retrieves the node weight for a given node ID.
• update: replaces an existing node at a given ID with a new one.It
  • Automatically stops and disconnects the old node.
  • Ensures all edges remain connected by reattaching the new node to neighbors.

Showcase

A new update workflow is enabled through the update method:

// Replace an oscillator node with a new one
const nodeId = graph.add(undefined)
graph.update(nodeId, new OscillatorNode(graph.getContext(), { frequency: 440 }))

Switching playback modes dynamically:

if (playback.completed()) {
  graph.update(nodeId, undefined) // stops and clears node automatically
}

Accessing a node:

const node = graph.get(nodeId)
if (node instanceof OscillatorNode) {
  node.frequency.value = 880
}

Migration guide

No breaking changes are introduced.

Checklist

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have added tests to cover my changes.