p5.plotSvg 0.3.0

This is a major release of p5.plotSvg, focused on p5.js add-on support and expanded p5.js version compatibility.

Highlights of this release:

• Adds support for the p5.js add-on API style, including instance methods such as sketch.beginRecordSvg() and
  sketch.endRecordSvg().
• Supports both p5.js v1 and p5.js v2 workflows, with testing against p5.js v1.11.13 and p5.js v2.3.0.
• Preserves backward compatibility with existing script-tag usage, the p5plotSvg namespace, and legacy global
  functions.
• Adds generated browser and ESM builds in dist/, while keeping the legacy lib/p5.plotSvg.js path available
  for existing CDN users.
• Expands automated browser tests for p5 v1/v2, global mode, instance mode, generated package builds, SVG
  escaping, path output, and Smorgasbord regression fixtures.

Distinctive p5.plotSvg features:

• Plotter-oriented SVG output: exports clean path geometry intended for pen plotters, laser cutters, CNC tools,
  and related vector workflows.
• Export-on-demand workflow: captures SVG only when beginRecordSvg() / endRecordSvg() are active, so normal
  animated sketches keep running at canvas speed.
• Backward-compatible API: supports legacy global functions, the p5plotSvg namespace, and newer add-on-style
  p5 instance methods.
• Instance-mode support: works in both p5 global mode and instance mode.
• SVG grouping tools: supports named SVG groups, optional Inkscape-compatible layer metadata, group merging, and
  stroke-color grouping for multi-pen workflows.
• Transform handling options: can preserve transform hierarchies as SVG groups or flatten transforms into per-
  element matrix attributes.
• Decimal precision controls: lets users tune coordinate and transform precision to balance file size and
  numeric fidelity.
• Numeric safety rails: detects malformed numeric values such as NaN and Infinity, with configurable
  sanitize-or-skip behavior.
• Large-coordinate protection: clamps extremely large finite coordinate values by default, with configurable
  clamp magnitude.
• No-op path filtering: omits degenerate SVG paths such as empty, move-only, and move/close-only paths.
• SVG escaping and validation: escapes user-provided text and attributes and validates injected XML names.
• Extension hooks: exposes experimental command, attribute, header, and <defs> injection hooks for advanced
  users and companion tools.
• Regression-tested output: includes Playwright browser tests covering p5 v1/v2, global/instance mode, package
  builds, path data, escaping, and broad, kitchen-sink-style Smorgasbord examples.

Known ongoing work:

• Full support for p5.js v2’s revised curve and spline implementations is still in progress.
• Exporting text as SVG outlines is still planned but not yet implemented.
• clip(), beginClip(), and endClip() remain intentionally unsupported for SVG export, because plotter-safe
  clipping requires extensive computational geometry and path splitting.