web: interface guidelines findings #249

Findings from a review of the web templates and style.css against the Vercel Web Interface Guidelines.

• Typed-name confirm missing on actions that remove access or grant admin: org member remove, team member remove, team repository revoke, and Promote on /admin/users.
• Form fields: the register email field is type="text"; email, username, one-time-code and SSH key fields lack autocomplete/spellcheck; identifier inputs (repo, org, file names, usernames, labels) are spell-checked.
• The MR close field shows !N but refuses !12, and inputmode="numeric" has no ! key.
• refs.html: aria-label overrides the visible labels "Compare" / "with".
• The line-comment link is announced as a bare number.
• No theme-color; ... in placeholders; td.size without tabular numbers; .pathbar wraps long segments only below 40rem; .refdrop chains scroll to the page; .issuetitle unbalanced.

Not changed: the side column's h2s precede the page h1 on the list pages; moving the column after the content breaks the focus order #237 relies on.