diff --git a/internal/server/document_revision_handlers.go b/internal/server/document_revision_handlers.go
index 916cb9e5..d7a3b1bc 100644
--- a/internal/server/document_revision_handlers.go
+++ b/internal/server/document_revision_handlers.go
@@ -1,8 +1,10 @@
 package server
 
 import (
+	"context"
 	"encoding/json"
 	"errors"
+	"fmt"
 	"net/http"
 	"strconv"
 	"strings"
@@ -198,11 +200,20 @@ func (s *Server) handleDocRevisionPatchContent(w http.ResponseWriter, r *http.Re
 	}
 
 	// 1) Controlled: author duty + lease WITHOUT writing body (fail-closed before ledger).
+	// This UI has no edit-session heartbeat: release the request-scoped human lease on every exit
+	// (success, 409, projection failure) so a 15m residual cannot block a later squad run.
 	if kind == "controlled" && s.svc != nil && s.svc.DocGov() != nil {
 		if err := s.svc.DocGov().AssertHumanCanEdit(r.Context(), docID, user.ID, docgov.RoleAuthor); err != nil {
 			writeDocGovError(w, err)
 			return
 		}
+		holderID := fmt.Sprintf("%d", user.ID)
+		if user.ID <= 0 {
+			holderID = "human_anon"
+		}
+		defer func() {
+			_, _ = s.svc.DocGov().ReleaseLease(context.Background(), docID, string(docgov.LeaseHolderHuman), holderID)
+		}()
 	}
 
 	// 2) Bootstrap if needed, then commit ledger. No fact-source mutation yet.
diff --git a/internal/server/document_revision_patch_order_test.go b/internal/server/document_revision_patch_order_test.go
index 558951b2..d06bc709 100644
--- a/internal/server/document_revision_patch_order_test.go
+++ b/internal/server/document_revision_patch_order_test.go
@@ -12,6 +12,7 @@ import (
 	"testing"
 	"time"
 
+	"chat-agent-system/internal/docgov"
 	"chat-agent-system/internal/docrevision"
 )
 
@@ -64,6 +65,7 @@ func TestDocRevision_PatchOrder_AssertBeforeLedger_ProjectionFailureKeepsLedger(
 	if after.HeadRevisionNo <= beforeRev && after.HeadSnapshotID == beforeSnap {
 		t.Fatalf("ledger should commit before projection; before rev=%d snap=%d after=%+v", beforeRev, beforeSnap, after)
 	}
+	assertHumanLeaseReleasedSquadCanAcquire(t, srv, docID)
 }
 
 func TestDocRevision_PatchOrder_LeaseDeniedDoesNotAdvanceLedger(t *testing.T) {
@@ -150,4 +152,73 @@ func TestDocRevision_PatchOrder_SaveDocumentContentSetsAuthorAudit(t *testing.T)
 	if _, err := os.Stat(filepath.Join(workDir, "output.md")); err != nil {
 		t.Fatalf("output.md should exist after SaveDocumentContent: %v", err)
 	}
+	assertHumanLeaseReleasedSquadCanAcquire(t, srv, docID)
+}
+
+func TestDocRevision_PatchReleasesHumanLeaseOnHeadConflict(t *testing.T) {
+	srv := newTestServer(t)
+	ctx := context.Background()
+	workDir := filepath.Join(srv.dataRoot(), "ws-conflict-lease")
+	_ = os.MkdirAll(workDir, 0o755)
+	docID := "doc_proj1_patch_conflict_lease"
+
+	if _, err := srv.svc.DocGov().CreateOrGetDocument(ctx, docID, 1, "intake", "摸底", "V0.1", workDir, 1, "admin", 2, "r", 3, "a"); err != nil {
+		t.Fatal(err)
+	}
+	st, err := srv.svc.DocRevision().OpenTemplateVersion(ctx, docID, "# base\n\nbody\n", docrevision.ActorSnapshot{DisplayName: "t"}, 1, workDir)
+	if err != nil {
+		t.Fatal(err)
+	}
+	token := loginTestAdmin(t, srv)
+	etag := `"` + strconv.FormatInt(st.HeadSnapshotID, 10) + ":" + strconv.Itoa(st.HeadRevisionNo) + `"`
+
+	first := httptest.NewRequest(http.MethodPatch, "/api/v1/documents/"+docID+"/content",
+		bytes.NewReader([]byte(`{"markdown":"# base\n\nbody\n\nA1\n"}`)))
+	withBearerAuth(first, token)
+	first.Header.Set("Idempotency-Key", "conflict-lease-a1")
+	first.Header.Set("If-Match", etag)
+	w1 := httptest.NewRecorder()
+	srv.Routes().ServeHTTP(w1, first)
+	if w1.Code != http.StatusOK {
+		t.Fatalf("first save want 200 got %d %s", w1.Code, w1.Body.String())
+	}
+
+	second := httptest.NewRequest(http.MethodPatch, "/api/v1/documents/"+docID+"/content",
+		bytes.NewReader([]byte(`{"markdown":"# base\n\nbody\n\nA2\n"}`)))
+	withBearerAuth(second, token)
+	second.Header.Set("Idempotency-Key", "conflict-lease-a2")
+	second.Header.Set("If-Match", etag)
+	w2 := httptest.NewRecorder()
+	srv.Routes().ServeHTTP(w2, second)
+	if w2.Code != http.StatusConflict {
+		t.Fatalf("stale etag want 409 got %d %s", w2.Code, w2.Body.String())
+	}
+	assertHumanLeaseReleasedSquadCanAcquire(t, srv, docID)
+}
+
+func assertHumanLeaseReleasedSquadCanAcquire(t *testing.T, srv *Server, docID string) {
+	t.Helper()
+	ctx := context.Background()
+	doc, err := srv.svc.DocGov().GetDocument(ctx, docID)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if doc.HasActiveLease(time.Now()) {
+		t.Fatalf("human lease must be released after PATCH, holder=%s/%s", doc.LeaseHolderType, doc.LeaseHolderID)
+	}
+	leased, err := srv.svc.DocGov().AcquireLease(ctx, docgov.LeaseAcquireRequest{
+		DocID:      docID,
+		HolderType: docgov.LeaseHolderSquad,
+		HolderID:   "run_after_human_save",
+		TTL:        time.Minute,
+	})
+	if err != nil {
+		t.Fatalf("squad must acquire after human PATCH released lease: %v", err)
+	}
+	if leased.LeaseHolderType != docgov.LeaseHolderSquad {
+		t.Fatalf("want squad holder, got %s", leased.LeaseHolderType)
+	}
+	if _, err := srv.svc.DocGov().ReleaseLease(ctx, docID, string(docgov.LeaseHolderSquad), "run_after_human_save"); err != nil {
+		t.Fatal(err)
+	}
 }