diff --git a/phase-ends/current/discussions/D1.md b/phase-ends/current/discussions/D1.md
new file mode 100644
index 0000000000..17fd4673b4
--- /dev/null
+++ b/phase-ends/current/discussions/D1.md
@@ -0,0 +1,14 @@
+# D1 — - (2026-09-29, session router)
+Status: executed
+
+## Decisions
+- (one line each)
+
+## Plan edits
+- (plan_edit.py commands; executed: yes/no)
+
+## Open
+- (unresolved items)
+
+## Deferred
+- deferred: <what> → <phase>
diff --git a/phase-ends/current/discussions/INDEX.md b/phase-ends/current/discussions/INDEX.md
index e63131e9e4..846e2516e0 100644
--- a/phase-ends/current/discussions/INDEX.md
+++ b/phase-ends/current/discussions/INDEX.md
@@ -1 +1,2 @@
 <!-- Discussion records for one phase. One line per record, written by tools/discussion.py off --new-record: D<n> | <topic> | <date> | discussions/D<n>.md -->
+D1 | - | 2026-09-29 | executed | phase-ends/current/discussions/D1.md
diff --git a/phase-ends/current/logs/T0.c1.md b/phase-ends/current/logs/T0.c1.md
new file mode 100644
index 0000000000..cc18c33e11
--- /dev/null
+++ b/phase-ends/current/logs/T0.c1.md
@@ -0,0 +1,5 @@
+# T0.c1 — launch.py PhaseEnd sort key
+- Change: tools/launch.py `_audit_flag_line`: local `_sort_key` (int/str mixed list → TypeError on id `3_5`) replaced by `phaseend_index.natural_key(item[1])` (tuple-typed parts, splits on `._-`).
+- Verified: `python3 tools/launch.py --seed-only` → exit 0, `mode=router`, 0 `refused:` lines (.run/logs/launch_seed.log).
+- Verified: scratch sort over phase-ends/ (39 PhaseEnds) → newest `PhaseEnd_Phase37.5.md` (id 37.5).
+- Note: launch.py now diverges from upstream PA3; expect an upgrade conflict until upstream fixes it. No PhaseEnd renamed.
diff --git a/tools/launch.py b/tools/launch.py
index 111ab683f5..7e59926e34 100644
--- a/tools/launch.py
+++ b/tools/launch.py
@@ -347,11 +347,9 @@ def _audit_flag_line(root):
                     pe_files.append((os.path.join(sub, name), m.group(1)))
     if not pe_files:
         return None
-    # natural sort: split phase id into numeric parts
-    def _sort_key(item):
-        parts = re.split(r"[.\-]", item[1])
-        return [int(p) if p.isdigit() else p for p in parts]
-    pe_files.sort(key=_sort_key)
+    # natural sort by phase id (type-safe: ids like 3_5 mix digits and words)
+    from phaseend_index import natural_key
+    pe_files.sort(key=lambda item: natural_key(item[1]))
     newest_rel, newest_phase = pe_files[-1]
     newest_path = os.path.join(pe_dir, newest_rel)
     # count '- flag:' lines under '## Audit'