The docs kept three hooks alive after the code deleted them

Purge leftover from #3835 · closes #3850 · 2026-08-31

How it surfaced

Two hooks blocked a session on this machine hours after they were deleted: one refused a standard IFS=$'\t' read, the other refused an rm string that was a quoted filter argument, never a command. Both were already gone from main; the session was running the pre-purge build. Looking them up is what found the docs still describing them as current features.

What was actually stale

surfacestate
3 spotlight pages, hand-writtendocumenting deleted hooks as live
3 mirrored copies under reference/generated by scripts/build-docs.sh, byte-identical
meta.json nav3 of 8 entries pointed at them
4 surviving spotlight pagescross-linked to the three, so deleting only the pages would have left dangling links

The issue said six pages. Six was the count of dedicated pages; the coherent unit is eleven files, because a page is not just a file, it is also a nav entry and whatever links to it. Deleting the smaller set would have made the site worse, not better.

Not fixed here, and stated rather than quietly skipped

dangerous-command-blocker   21 files   43 mentions
file-guard                  18 files   33 mentions
block-writes                11 files   18 mentions

Of those, only the spotlights were DEDICATED pages. The rest is prose in 21
hand-written files (cookbook, troubleshooting, foundations, getting-started)
that uses these hooks as the worked example while explaining a concept.

Rewriting an explanation around a different example is editorial work, not a
delete, so it is a separate pass rather than something to rush behind a
mechanical cleanup.

Verified

grep for spotlights/{the three}   ->  no dangling link remains
reference/hooks/spotlights/       ->  the three copies gone after build-docs.sh
check-docs-facts.mjs              ->  OK (floor 2.1.251, 106 skills, 36 agents, 172 hooks)