diff --git a/docs/roadmaps/barc-01-useful-play.md b/docs/roadmaps/barc-01-useful-play.md
index 4ab1f3a..39132d0 100644
--- a/docs/roadmaps/barc-01-useful-play.md
+++ b/docs/roadmaps/barc-01-useful-play.md
@@ -258,3 +258,36 @@ Protected source delivery and the fresh packet's independent source/build,
 configuration, current-process and actually loaded engine/plugin joins remain
 required. RP3 actual capacity, RP4 custody, RP5 bounded Count1 and useful-play
 journeys remain open at **0/6**.
+
+## RP4 bounded stock attempt and complete map census repair — 2026-10-03
+
+The independently reviewed protected `a7eb52a` packet received one prospective
+Count1 grant. Its sole attempt refused before browser launch or Count1 in
+17.234 seconds. The actual browser admission consumed 32 completed probes and
+one compiled-policy evaluation in 1,127,818 microseconds: its 159,096-byte log
+retained a stable 139-byte incomplete tail, so the shared probe cap exhausted
+before the five-second deadline. All owned host, engine and receiver processes
+settled; the complete 24,544-file packet and its immutable settings seed remained
+unchanged. The grant is consumed and the original attempt is preserved.
+
+The selected unmodified Recoil 2026.07.04 source writes newline-terminated records
+through a buffered file sink whose default flush threshold is ERROR. The observed
+console record continued beyond the file's incomplete tail. Three real libc FILE
+controls distinguish that buffered-prefix exposure from the official
+`LogFlushLevel = 0` configuration, which flushes every emitted record. A new
+immutable settings seed with that setting is prepared separately; neither a
+stable partial record nor a longer polling interval grants admission. The
+32-probe, three-evaluation, five-second, byte and exact-read limits stay fixed.
+
+Preparing positive loaded-custody receipts exposed a separate source defect:
+`proc_bytes` performed one unbuffered read, which may return before EOF on
+`/proc/<pid>/maps`. The repair reads bounded chunks through EOF and still refuses
+maximum-plus-one bytes. Five focused controls cover real complete process maps,
+short reads, exact-bound acceptance, over-bound refusal, empty input and invalid
+bounds. A private successor helper must persist the positive actual engine and
+plugin mapping census before browser effect; its actual-process controls are
+preparation evidence only. The source repair preserves the protected B1 adapter
+and receiver dependency correction. Protected delivery, a new fully reviewed
+source/build/configuration packet, actual loaded custody, actual successor
+capacity and a distinct bounded native grant remain required. RP3/RP4/RP5 and
+all useful-play journeys remain open at **0/6**.
diff --git a/tests/Broker.NativeProof/RuntimeEvidence/fixtures/complete-record-helper/runtime_identity.py b/tests/Broker.NativeProof/RuntimeEvidence/fixtures/complete-record-helper/runtime_identity.py
index 2e75674..37dec98 100644
--- a/tests/Broker.NativeProof/RuntimeEvidence/fixtures/complete-record-helper/runtime_identity.py
+++ b/tests/Broker.NativeProof/RuntimeEvidence/fixtures/complete-record-helper/runtime_identity.py
@@ -17,9 +17,14 @@ def mark_failure(error,check,outcome=None,policy_observation=None):
 
 def proc_bytes(pid,name,maximum):
     # The only proc files read are nonsecret stat/maps/fdinfo, never environ/cmdline.
+    need(type(maximum) is int and maximum>0,'proc positive byte bound')
+    chunks=[];length=0
     with open(f'/proc/{pid}/{name}','rb',buffering=0) as stream:
-        value=stream.read(maximum+1)
-    need(len(value)<=maximum,'proc byte bound');return value
+        while length<=maximum:
+            block=stream.read(min(65536,maximum+1-length))
+            if not block:break
+            chunks.append(block);length+=len(block)
+    need(length<=maximum,'proc byte bound');return b''.join(chunks)
 
 def start_ticks(pid):
     value=proc_bytes(pid,'stat',16384).decode();return value.rsplit(') ',1)[1].split()[19]
diff --git a/tests/Broker.NativeProof/RuntimeEvidence/fixtures/complete-record-helper/test_proc_bytes.py b/tests/Broker.NativeProof/RuntimeEvidence/fixtures/complete-record-helper/test_proc_bytes.py
new file mode 100644
index 0000000..86e07f9
--- /dev/null
+++ b/tests/Broker.NativeProof/RuntimeEvidence/fixtures/complete-record-helper/test_proc_bytes.py
@@ -0,0 +1,26 @@
+import io,os,pathlib,unittest
+from unittest.mock import patch
+from runtime_identity import proc_bytes
+from private_io import Refused
+
+class Chunked(io.BytesIO):
+    def read(self,n=-1):return super().read(min(n,7))
+
+class ProcBytes(unittest.TestCase):
+    def test_actual_proc_maps_reads_to_eof(self):
+        expected=pathlib.Path('/proc/self/maps').read_bytes();actual=proc_bytes(os.getpid(),'maps',4*1024*1024)
+        # Address mappings are read twice; assert full stable path census, not addresses.
+        paths=lambda b:{l.split(None,5)[5] for l in b.splitlines() if len(l.split(None,5))==6}
+        self.assertEqual(paths(actual),paths(expected));self.assertIn(b'libc.so.',actual);self.assertGreater(len(actual),4096)
+    def test_short_reads_continue_to_eof(self):
+        data=b'x'*100
+        with patch('builtins.open',return_value=Chunked(data)):self.assertEqual(proc_bytes(os.getpid(),'maps',100),data)
+    def test_maximum_plus_one_refused_after_short_reads(self):
+        with patch('builtins.open',return_value=Chunked(b'x'*101)):
+            with self.assertRaises(Refused):proc_bytes(os.getpid(),'maps',100)
+    def test_empty_proc_file(self):
+        with patch('builtins.open',return_value=Chunked(b'')):self.assertEqual(proc_bytes(os.getpid(),'maps',100),b'')
+    def test_nonpositive_bound_refused(self):
+        with self.assertRaises(Refused):proc_bytes(os.getpid(),'maps',0)
+
+if __name__=='__main__':unittest.main()