Backlog triage Part D: ROADMAP cleaned (161 -> 123 lines, 81 -> 42 KB): intentions re-sorted P2/P3/P4, each names its 00 row; 33 shipped/killed/closed/moved items + the pre-invite checklist -> ROADMAP-HISTORY; UPDATE-ARC collapsed; one_register_gate reads suffix ids (R-50b found, moved to OPEN-ITEMS; decoy seen red)

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0159rPz1ZhFKsS53msqPYxtS

scripts/test_gate_decoys.py

@@ -240,6 +240,15 @@ decoy("closed-register/open-row-closed-word (BY DESIGN)", "closed_register_gate.
       append_to(_OPEN_REG, _open_row("R-907", "**READY — RE-RANKED UP 2026-08-03 (R-86 closed)**")),
       expect="accept")
 
+# --- one-register (2026-10-03): an open ROADMAP row whose id carries a LETTER SUFFIX ------------
+# The gate's id pattern was `R-(\d+)`, so R-27b, R-27c and R-50b were never read. Fixing it convicted
+# R-50b at once — a finding that had lived only in ROADMAP.md. This decoy is that shape. (one-register
+# stays in decoy_coverage_gate's EXEMPT list for R-424's hole — a finding filed under `idea` — which
+# this decoy does not close.)
+decoy("one-register/suffix-id-row", "one_register_gate.py",
+      append_to(os.path.join(ROOT, "documentation", "backlog", "ROADMAP.md"),
+                u"\n| R-905b | **A finding filed only here.** | S | READY — 2026-10-03 | none |\n"))
+
 # --- hub-copy: an ENGLISH retrieval promise, planted in the bundle (R-558) -----------------------
 #
 # TWO SHAPES AT ONCE, and the second is why this decoy exists at all.