Final functional M5 iteration (spec ae905de, plan 67027ab; on
green m5.1 204c171 + m5.2 b724cd1 whose leak-proof resolved via
dbd76e5). Proves the chunk/window-boundary-invisibility claim the
M4 retirement rests on:
- adapter::fold_window — purely additive windowed sibling of
fold_symbol (same MidPriceStream+Kernel path; stream_tick_windowed).
fold_symbol/MidPriceStream/Kernel byte-untouched.
- chrono as a DEV-dep only — the time-shard test derives
(y,m)->Unix-ms bounds (data-server's own precedent) and passes
raw ms to the bin; the bin is date-math-free; Invariant 1
unaffected.
- new single-responsibility [[bin]] timeshard_runner — one thread
per disjoint window, each owning its Kernel (Ctx:!Send =>
compile-time per-thread-ctx).
- tests/timeshard.rs — spec §3 strength-ordered: (a) per-shard
(acc,n) BIT-EXACT vs single-thread host fold of that exact window
in stream order (THE boundary-invisibility proof); (b) Σ partials
bit-exact by construction; (c) whole-window within REL_TOL=1e-6
only (cross-shard f64 reassociation is host arithmetic, never a
kernel property — bit-exact there would be the bug; tolerance
derived from the recursive-summation error bound). Plus the
now-deterministic leak-Σ + a journal-only friction timing capture
(no bench gate, no timing assertion).
Concrete pin: EURUSD 2017-03/04/05 (recon-verified present,
contiguous, no gaps; data-server has no month-listing API). RED was
a genuine deterministic compile failure (declared-but-absent bin
source; Cargo missing-source error vs the plan's predicted env!
error — same cause, no false-green; benign plan-text imprecision in
Concerns).
Boss-verified independently: timeshard determinism 5/5 (no jitter);
full ail-embed suite 0 failed AND 0 ignored across all binaries
(m5.2 symbol_fan_swarm_leak_free stays un-ignored & green — the
saga's resolution intact); isolated embed_rc_global_stats_race
still green; AILang workspace data-server count 0; compiler-surface
diff empty (zero diff to crates/ailang-*, crates/ail/, runtime/,
examples/*.ail, root Cargo.toml, DESIGN.md).
Friction-harvest deliverable (P2 flat-array-decision input):
host-per-tick-FFI ~= 658 ms / 3,192,562 ticks ~= ~206 ns/tick at
real EURUSD volume.
M5 functional work complete; milestone closes next via the
mandatory audit (which also handles the pre-existing
DESIGN.md:2358-2360 "additive M4 concern" drift, out of m5.3 scope).
Includes the per-iter journal, stats, and the INDEX.md line.
