fix(paste): respect tool sanitize config for paste tags (Fixes #2984) - #3019

What does this PR do?

Fixes #2984 — pasteConfig ignores tool's sanitize rules.

Problem

When pasting HTML content, the paste module builds its sanitizer config only from the tool's pasteConfig.tags. When a tool declares its tags as plain strings (e.g. tags: ['P', 'DIV']), the sanitizationConfig for each tag is null, and the code falls back to {} — stripping all attributes from pasted elements.

Meanwhile the tool's static get sanitize() explicitly allows certain attributes (e.g. p: { style: true }). These rules are ignored during paste, so pasting from Google Docs loses paragraph indentation and other inline styles.

Fix

In Paste.processDataTransfer, when a tag has no explicit sanitization config from pasteConfig.tags, fall back to the tool's sanitizeConfig rules for that tag. Only if neither provides a rule do we strip all attributes.

Reproduction

class MyTool {
  static get pasteConfig() { return { tags: ['P', 'DIV'] }; }
  static get sanitize() { return { p: { style: true } }; }
  onPaste(event) { /* receives element */ }
}

Before: pasted <p style="text-indent: 36pt;"> becomes <p><span>...</span></p> (style stripped)
After: pasted <p style="text-indent: 36pt;"> is delivered to the tool with its style attribute preserved.

Checklist

• Build passes (vite build)
• No new type errors introduced