Phase 1 Core Routing: verify DoD complete, update tracking files

All Phase 1 DoD criteria verified:
- Rendezvous assignment deterministic (router.rs 100% coverage)
- Reshuffle bound on add ≤ 2×(1/4) (proptest + unit test)
- 64 shards/3 nodes/RF=1 → 17-26 per node (uniformity test)
- write_targets returns RG×RF nodes (acceptance tests)
- covering_set with replica rotation (acceptance tests)
- merger passes all merge/facet/limit tests
- miroir-core ≥ 90% line coverage (90.17% via tarpaulin)

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

.needle-predispatch-sha

@@ -1 +1 @@
-b2490ea64d3be84eca966545188bf3bd1ac98a16
+da2aa18e04543e7e70824e5a166b7694c0a2e5a9

tests/benches/score-comparability/results/experiment.json

@@ -1,12 +1,13 @@
 {
-  "corpus_dir": "corpus",
-  "query_file": "queries/queries.jsonl",
+  "corpus_dir": "tests/benches/score-comparability/corpus",
+  "query_file": "tests/benches/score-comparability/queries/queries.jsonl",
   "shard_count": 10,
   "limit": 100,
   "total_queries": 10000,
   "merge_strategies": [
     "score",
-    "rrf"
+    "rrf",
+    "dfs"
   ],
   "rrf_k": 60,
   "global_stats": {