Review nits: the walk's start needs no clamp, and the invariant needs one copy

src/markdown/parse/markdown-to-adf.test.ts

@@ -841,7 +841,6 @@ test('leaves the brackets of a link whose text already holds one the text they a
   ])
 })
 
-// Literal brackets hold what no mark may, so the openers they doom give way before closeLink refuses a carry or an image inside them.
 test('keeps the carry and the image the brackets a nested link leaves literal hold', () => {
   assert.deepEqual(content(markdownToAdf('[[<http://x/>](/c)!adf:carry{json="{\\"type\\":\\"blockCard\\"}"}](/w)\n')), [
     { content: [text('[['), marked('http://x/', link('http://x/')), text('](/c)'), { type: 'blockCard' }, text('](/w)')], type: 'paragraph' },