main green: reserve llms.txt; the list test looks for the visible report link #736

Two gate tests went red where merges crossed (#705 with #675 and #683).

• /llms.txt is a top-level page, so it joins the reserved names.
• The issue-list test asserted that a signed-in page has no report href at all; the page head now carries a rel=help link for agents on every public repository page. The test now refuses a visible report link for someone signed in.

Verified: reserved-names, studio, gate-list, check-list and hollow tests pass (215); tsc clean.

🤖 Generated with Claude Code