docs: seed-lottery marginality is placement-level (Heisenbug evidence)

[gHashTag]

Records a measured negative result from the on-silicon training work: an attempt at on-chip observability (widening the UART result dump to expose the hidden pre-activations z0/z1 alongside the output y) flipped the design from marginally-computing to all-zero output. The extra logic re-placed the shared core past its (unconstrained) timing edge — a genuine Heisenbug that is itself evidence the seed-lottery fault is a placement/timing property of the whole deep combinational path, not a localizable single-register bug. The remedy is a real multicycle timing constraint (commercial P&R), not an RTL change.

Docs-only; no code or gate changes. Refs #1764

[github-actions]

PR Dashboard

Generated at: 2026-08-07 19:10:48 UTC

• docs: seed-lottery marginality is placement-level (Heisenbug evidence) #1895 docs: seed-lottery marginality is placement-level (Heisenbug evidence) | Created: 2026-08-07 | Updated: 2026-08-07 | 11 failing / 15 total
• chore: civilian mesh positioning — drop drone wording (bpsk.t27) #1874 chore: civilian mesh positioning — drop drone wording (bpsk.t27) | Created: 2026-08-07 | Updated: 2026-08-07 | 2 failing / 25 total
• feat(igla): Wave Loop 897 — module-scope [613][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1858 feat(igla): Wave Loop 897 — module-scope [613][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-07 | Updated: 2026-08-07 | 1 failing / 3 total
• feat(igla): Wave Loop 896 — module-scope [611][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1856 feat(igla): Wave Loop 896 — module-scope [611][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-07 | Updated: 2026-08-07 | 1 failing / 3 total
• feat(igla): Wave Loop 895 — module-scope [609][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1854 feat(igla): Wave Loop 895 — module-scope [609][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-07 | Updated: 2026-08-07 | 1 failing / 3 total
• feat(igla): Wave Loop 894 — module-scope [607][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1852 feat(igla): Wave Loop 894 — module-scope [607][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-07 | Updated: 2026-08-07 | 1 failing / 3 total
• feat(igla): Wave Loop 893 — module-scope [605][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1850 feat(igla): Wave Loop 893 — module-scope [605][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-07 | Updated: 2026-08-07 | 1 failing / 3 total
• feat(igla): Wave Loop 892 — module-scope [603][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1847 feat(igla): Wave Loop 892 — module-scope [603][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-07 | Updated: 2026-08-07 | 1 failing / 3 total
• feat(igla): Wave Loop 891 — module-scope [601][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1844 feat(igla): Wave Loop 891 — module-scope [601][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-07 | Updated: 2026-08-07 | 0 failing / 4 total
• feat(igla): Wave Loop 890 — module-scope [599][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1842 feat(igla): Wave Loop 890 — module-scope [599][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-07 | Updated: 2026-08-07 | 0 failing / 4 total
• feat(igla): Wave Loop 883 — module-scope [585][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1815 feat(igla): Wave Loop 883 — module-scope [585][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-06 | Updated: 2026-08-06 | 0 failing / 1 total
• feat(igla): Wave Loop 882 — module-scope [583][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1813 feat(igla): Wave Loop 882 — module-scope [583][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-06 | Updated: 2026-08-06 | 0 failing / 12 total
• feat(igla): Wave Loop 881 — module-scope [581][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1810 feat(igla): Wave Loop 881 — module-scope [581][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-06 | Updated: 2026-08-06 | 0 failing / 12 total

Summary

Status	Count
Total Open PRs	13
PRs with Failing Checks	2
PRs with All Checks Green	11
READY	5
FAILING	2
PENDING	0

Seal Status

• ⚠️ STALE -- sha256(compiler.rs)=f74459fc23c3 != manifest seal=87e5cbd3ad94.
  The committed NMSE numbers were certified against an older compiler.rs.
  Run scripts/reseal-check.sh locally for the two-step reseal command (advisory; not a merge gate).

[github-actions]

📓 NotebookLM Notebook linked to this PR

• Notebook ID: b83263109fb055dc
• URL: https://notebooklm.google.com/notebook/b83263109fb055dc

This notebook contains session context, decisions, and artifacts for this work.

[github-actions]

PR Dashboard

Generated at: 2026-08-07 19:12:23 UTC

• docs: seed-lottery marginality is placement-level (Heisenbug evidence) #1895 docs: seed-lottery marginality is placement-level (Heisenbug evidence) | Created: 2026-08-07 | Updated: 2026-08-07 | 12 failing / 17 total
• chore: civilian mesh positioning — drop drone wording (bpsk.t27) #1874 chore: civilian mesh positioning — drop drone wording (bpsk.t27) | Created: 2026-08-07 | Updated: 2026-08-07 | 2 failing / 25 total
• feat(igla): Wave Loop 897 — module-scope [613][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1858 feat(igla): Wave Loop 897 — module-scope [613][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-07 | Updated: 2026-08-07 | 1 failing / 3 total
• feat(igla): Wave Loop 896 — module-scope [611][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1856 feat(igla): Wave Loop 896 — module-scope [611][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-07 | Updated: 2026-08-07 | 1 failing / 3 total
• feat(igla): Wave Loop 895 — module-scope [609][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1854 feat(igla): Wave Loop 895 — module-scope [609][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-07 | Updated: 2026-08-07 | 1 failing / 3 total
• feat(igla): Wave Loop 894 — module-scope [607][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1852 feat(igla): Wave Loop 894 — module-scope [607][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-07 | Updated: 2026-08-07 | 1 failing / 3 total
• feat(igla): Wave Loop 893 — module-scope [605][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1850 feat(igla): Wave Loop 893 — module-scope [605][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-07 | Updated: 2026-08-07 | 1 failing / 3 total
• feat(igla): Wave Loop 892 — module-scope [603][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1847 feat(igla): Wave Loop 892 — module-scope [603][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-07 | Updated: 2026-08-07 | 1 failing / 3 total
• feat(igla): Wave Loop 891 — module-scope [601][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1844 feat(igla): Wave Loop 891 — module-scope [601][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-07 | Updated: 2026-08-07 | 0 failing / 4 total
• feat(igla): Wave Loop 890 — module-scope [599][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1842 feat(igla): Wave Loop 890 — module-scope [599][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-07 | Updated: 2026-08-07 | 0 failing / 4 total
• feat(igla): Wave Loop 883 — module-scope [585][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1815 feat(igla): Wave Loop 883 — module-scope [585][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-06 | Updated: 2026-08-06 | 0 failing / 1 total
• feat(igla): Wave Loop 882 — module-scope [583][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1813 feat(igla): Wave Loop 882 — module-scope [583][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-06 | Updated: 2026-08-06 | 0 failing / 12 total
• feat(igla): Wave Loop 881 — module-scope [581][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1810 feat(igla): Wave Loop 881 — module-scope [581][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes | Created: 2026-08-06 | Updated: 2026-08-06 | 0 failing / 12 total

Summary

Status	Count
Total Open PRs	13
PRs with Failing Checks	2
PRs with All Checks Green	11
READY	5
FAILING	2
PENDING	0

Seal Status

• ⚠️ STALE -- sha256(compiler.rs)=f74459fc23c3 != manifest seal=87e5cbd3ad94.
  The committed NMSE numbers were certified against an older compiler.rs.
  Run scripts/reseal-check.sh locally for the two-step reseal command (advisory; not a merge gate).

[github-actions]

📓 NotebookLM Notebook linked to this PR

• Notebook ID: b83263109fb055dc
• URL: https://notebooklm.google.com/notebook/b83263109fb055dc

This notebook contains session context, decisions, and artifacts for this work.

[gHashTag]

Superseded by a single-commit PR with per-commit issue reference (L1 traceability).