fix(inline-css): stop reformatting inline style attributes

The post-process pass added a space after every `:` and `;`, which broke
URLs in inline style values (`url('https://...')` → `url('https: //...')`)
and forced visual consistency with Juice's spaced output that email
clients don't care about. Dropped the colon/semicolon rewriting and the
trailing-semicolon ensure; kept `preferUnitlessValues` (0px → 0) and
gated its walk on the option being enabled.

Author: cossssmin

src/tests/transformers/inlineCss.test.ts

@@ -217,4 +217,25 @@ describe('inlineCss', () => {
       expect(result).not.toContain('style=')
     })
   })
+
+  describe('pre-existing inline styles are passed through verbatim', () => {
+    it('does not inject a space inside https:// in url()', () => {
+      const html = `<div style="background-image:url('https://example.com/img.jpg')">x</div>`
+      const result = run(html, true)
+      expect(result).toContain("background-image:url('https://example.com/img.jpg')")
+      expect(result).not.toContain('https: //')
+    })
+
+    it('preserves data: URIs in url()', () => {
+      const html = `<div style="background-image:url('data:image/png;base64,iVBORw0KG')">x</div>`
+      const result = run(html, true)
+      expect(result).toContain("background-image:url('data:image/png;base64,iVBORw0KG')")
+    })
+
+    it('preserves URLs with query strings containing colons or ampersands', () => {
+      const html = `<div style="background-image:url('https://cdn.example.com/img.jpg?expires=1700000000&sig=abc')">x</div>`
+      const result = run(html, true)
+      expect(result).toContain("url('https://cdn.example.com/img.jpg?expires=1700000000&sig=abc')")
+    })
+  })
 })

src/transformers/inlineCss.ts

@@ -153,33 +153,19 @@ export function inlineCssDom(dom: ChildNode[], options: InlineCssOptions = {}):
     return dom
   }
 
-  // Post-process for preferUnitlessValues
   const result = parse(inlinedHtml)
 
-  walk(result, (node) => {
-    const el = node as Element
-    if (el.attribs?.style) {
-      // Normalize style formatting: ensure spaces after : and ;
-      let style = el.attribs.style
-        .replace(/:\s*/g, ': ')
-        .replace(/;\s*/g, '; ')
-        .trimEnd()
-
-      // Ensure trailing semicolon
-      if (!style.endsWith(';')) {
-        style += ';'
-      }
-
-      if (preferUnitlessValues) {
-        style = style.replace(
+  if (preferUnitlessValues) {
+    walk(result, (node) => {
+      const el = node as Element
+      if (el.attribs?.style) {
+        el.attribs.style = el.attribs.style.replace(
           /\b0(px|rem|em|%|vh|vw|vmin|vmax|in|cm|mm|pt|pc|ex|ch)\b/g,
           '0'
         )
       }
-
-      el.attribs.style = style
-    }
-  })
+    })
+  }
 
   /**
    * Restore `embed` from our marker so the purge step can detect