P3 review: the surface, docs and proofs

Split kernel::entry_flows into entry_movements and flows_of so the
reversal-mirror proof fits CI; prove runs the fast harnesses, prove-slow
the 8 slow ones (own job in scheduled CI), prove-all both. Laws in
verification.md renumbered 1-31 with a table of all 55 harnesses.

MCP docs checked against the 115 tools (about 60 fixes) with a test that
every tool is documented; rules.md cross-references fixed; bookspec
statuses and loader tightened; viewer notes wrap and accounts sort by
code; STATUS.md says P3 is built, cutover pending.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01T3gXMVt7XJPi6ens1or9Dj

bookspec/examples/p3-party-gift-card-is-a-promise.toml

@@ -16,7 +16,7 @@ owes its customers in service (deferred revenue), a promise. Selling one
 is money received from the buyer; redeeming it moves no money and counts
 nothing.
 """
-status = "CONVENTION"
+status = "CHOICE"
 sources = [
   "DECISION (owner, 2026-10-20): money is cash, cards, the members' financing and loans; every other liability is a promise, counted when settled (wanderbooks rules.md B-35 item 5)",
   "Helvering v. Price, 309 U.S. 409, 412-413 (1940): a promise to pay is not payment (docs/spec/sources/helvering-v-price-1940.md)",