Final functional M5 iteration (spec ae905de; builds on green
m5.1 204c171 + m5.2 b724cd1 whose leak-proof is resolved through
dbd76e5). 3 tasks: (1) additive adapter::fold_window (windowed
sibling of fold_symbol) + chrono dev-dep + a second
[[bin]] timeshard_runner declaration; (2) tests/timeshard.rs
written FIRST — RED is the deterministic `env!(CARGO_BIN_EXE_
timeshard_runner) not defined` compile failure (bin absent); (3)
the timeshard_runner bin → GREEN, with the spec §3 strength-ordered
assertions (a) per-shard bit-exact vs single-thread windowed host
fold (THE boundary-invisibility proof), (b) Σ bit-exact by
construction, (c) whole-window within REL_TOL=1e-6 (derived from
the recursive-summation error bound, never bit-exact — spec
explicit), plus the now-deterministic leak-Σ and a journal-only
friction-timing capture.
Boss decisions in-plan: new bin not an arg-mode (shipped symbol-fan
path byte-untouched, no regression surface); chrono dev-only (date
math in the test, bin date-math-free; Invariant 1 unaffected);
concrete pin EURUSD 2017_03/04/05 (recon-verified present, no
gaps; data-server has no month-listing API); friction is a journal
observation, no bench gate, no timing assertion (flake-free);
pre-existing DESIGN.md:2358-2360 M4-drift explicitly out of scope.
Milestone close + mandatory audit run after Boss-verification.
Brummel
67027ab0f9