Live 1.5.0 use caught the gate blocking a decision note over the single
vault-common token "echo" (min-normalized overlap gives any one-token
entity a 1.0 score). New echo_index.gate_candidates() + token_df():
- gate blocks same-kind candidates only; cross-kind name collisions
(a decision titled after its project) warn instead of blocking
- a lone shared token blocks only when unique to that entity (df == 1);
multi-token overlaps still block
fuzzy_candidates (advisory warnings) and exit-76/--merge-into/--force
semantics unchanged. +3 offline unit tests, gate e2e cases restructured
+2 new; verified live both directions. All suites green.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>