ops(erp-tune): stage + launch R47 ERP-seat SFT run 5 on pfi-gx10

Run 5 = the dependency-forcing corpus arm: airoboros-3.2 OUT of the 20% slot,
govreport/clean-v1 (496) + qmsum/clean-v1 (97) IN, at run 4's lr 2e-04 with
everything else held. kvasir byte-identical (survivors-r5 = survivors-r4 minus
airoboros plus the two new roots whole). Operator authorized the launch to
infra-ops directly; grant operator-2026-09-07-rnd-run5.

Canonical copies of the config, launcher and survivors builder; runbook
docs/runbooks/gx10-run-05.md. Launch gates all passed (7/7 root shas + shard
hashes, survivor join 8,212 = recipe, holdout disjoint, window_count==1 on all
593 slot rows, realized [mix] slot loss 3.46% vs preregistered 3.4%). 524 steps.
persistent-memory current-state updated: run 5 LAUNCHED + training.

scripts/erp-tune-gx10/build_r5_survivors.py

@@ -0,0 +1,47 @@
+import json, hashlib, collections
+
+R4  = "/home/infra-ops/erp-tune/recipe-r4/survivors-r4.jsonl"
+GOV = "/home/infra-ops/erp-tune/datasets/derived/govreport/clean-v1/govreport-clean-v1.jsonl"
+QMS = "/home/infra-ops/erp-tune/datasets/derived/qmsum/clean-v1/qmsum-clean-v1.jsonl"
+OUT = "/home/infra-ops/erp-tune/recipe-r5/survivors-r5.jsonl"
+
+# Start from run-4's survivors: they already carry the EXACT held dialogue
+# selection (c2-logs 301 / cwm 183 / bluemoon 126), fireball whole (5,396) and
+# kvasir's exact 1,613-sample prefix cut. Reusing them is what guarantees kvasir
+# is byte-identical to run 4 -- NOT re-cut (run-5 recipe held clause).
+r4 = [json.loads(l) for l in open(R4)]
+rows = [r for r in r4 if r["dataset_id"] != "airoboros-3.2"]
+
+c = collections.Counter(r["dataset_id"] for r in rows)
+held = {"c2-logs-32k-llama3": 301, "creative-writing-multiturn": 183,
+        "bluemoon": 126, "fireball": 5396, "kvasir": 1613}
+assert set(c) == set(held), "unexpected dataset_id set after airoboros removal: %s" % dict(c)
+for k, v in held.items():
+    assert c[k] == v, "HELD ROOT CHANGED: %s %d != %d" % (k, c[k], v)
+print("  held (dialogue+fireball+kvasir) unchanged:", dict(c))
+
+def append_root(path, dsid, expect):
+    n = 0
+    seen = set()
+    for l in open(path):
+        d = json.loads(l)
+        assert d["id"] not in seen, "dup id in %s: %s" % (dsid, d["id"])
+        seen.add(d["id"])
+        rows.append({"dataset_id": dsid, "id": d["id"]})
+        n += 1
+    assert n == expect, "%s: %d != %d" % (dsid, n, expect)
+    print("  %s appended: %d" % (dsid, n))
+
+append_root(GOV, "govreport", 496)
+append_root(QMS, "qmsum", 97)
+
+expected_total = 301 + 183 + 126 + 5396 + 1613 + 496 + 97  # 8212
+assert len(rows) == expected_total, "%d != %d" % (len(rows), expected_total)
+
+with open(OUT, "w") as f:
+    for r in rows:
+        f.write(json.dumps(r, separators=(",", ":"), sort_keys=True) + "\n")
+sha = hashlib.sha256(open(OUT, "rb").read()).hexdigest()
+print("  wrote %s survivors -> %s" % (format(len(rows), ","), OUT))
+print("  final composition:", dict(collections.Counter(r["dataset_id"] for r in rows)))
+print("  sha256 %s" % sha)