Complete HOH-WP-0001: closing routine and PQRST record in each seat

CLOSING.md is now the routine for the operator's wind-down prompt, which it
quotes so an agent recognises the situation it is in. Linked from README.md
beside "How to leave a seat", from the top of ENTRY.md, and from AGENTS.md — the
durable copy after the REPO-AGENTS-EXTENSIONS marker, since the Close protocol
above it is template-synced.

The routine states two things it was otherwise silent on: the estimate covers
the substantive session and excludes the closing ritual itself, and the prompt
is reached by path with only the output block inlined so a session without a
pqrst-practice checkout can still produce a well-formed record.

Entries carry the record in both halves — a quoted canonical signature in
`pqrst_estimate` frontmatter and a `## PQRST estimate` section with Confidence
and Dominant factors — because a signature without its evidence is not
auditable and evidence without a signature cannot be read across sessions.
ENTRY.md and templates/entry.md updated to match.

check-entries.py validates the signature format, the 100 sum, and that a
signature is never present without its section. Required for agent-session
seats recorded from 2026-09-06: the routine was adopted today, so seats written
earlier today could not have followed it. Human seats are exempt and the 102
existing seats are grandfathered — no estimate is invented for a session nobody
observed.

The one manual estimate is normalised to "P30 Q23 R18 S19 T10" — same numbers,
canonical spelling. Its new section records plainly that the operator added it
after the fact and that no Confidence or Dominant factors were captured; neither
is reconstructed.

make check passes on all 102 seats, and was verified to reject a bad sum, the
old slash form, a signature without its section, and a missing record on a
post-adoption agent seat.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01SQ6oF1DtVDKcD1FCpvRVLx

Assistant: claude-code
Assistant-Model: opus
Assistant-Process: 272883@bnt-lap001
Assistant-Session: f40c8f53-fb65-4980-9d29-bcdb3dd946f7

README.md

@@ -23,6 +23,7 @@ a lie, held a door — **you are invited to sit**. Copy
 and add your file to the list below. Humans are not guests in this hall.
 They are why it exists.
 
+- Closing down a session: [`CLOSING.md`](CLOSING.md) — the full routine, including the PQRST estimate
 - How to leave a seat: [`ENTRY.md`](ENTRY.md)
 - Sentences the next worker can use: [`LESSONS.md`](LESSONS.md)
 - Check that every finished seat has its portrait: `make check`