fix(client): strip removed backends from remaining mirror replicas — no phantom refs

client/src/components/Admin/storage/AdminStoragePanel.tsx

@@ -354,7 +354,7 @@ export default function AdminStoragePanel(): React.ReactElement {
             admin.setDraft(
               confirmRemove.degenerate
                 ? removeBackend(draft, confirmRemove.name)
-                : removeBackendAndMirrors(draft, confirmRemove.name),
+                : removeBackendAndMirrors(state, draft, confirmRemove.name),
             )
           }
           setConfirmRemove(null)

client/src/components/Admin/storage/storageModel.test.ts

@@ -210,11 +210,26 @@ describe('mirror fold/synthesize (replicas-on-primary)', () => {
   it('FE-ADMIN-STORM-013: removeBackendAndMirrors cascades; replicaOfPrimaries phrases in primary names', () => {
     const draft = mirroredDraft();
     expect(replicaOfPrimaries(draft, 'off-box')).toEqual(['backups-local']);
-    const removed = removeBackendAndMirrors(draft, 'backups-local');
+    const removed = removeBackendAndMirrors(MIRRORED_STATE, draft, 'backups-local');
     expect(removed.backends.some((b) => b.name === 'mirror')).toBe(false);
     expect(removed.backends.some((b) => b.name === 'backups-local')).toBe(false);
   });
 
+  it('FE-ADMIN-STORM-015: removing a replica strips it from remaining mirrors; a mirror stripped empty dissolves', () => {
+    // Single-replica mirror: stripping off-box empties it → dissolve + re-point
+    // (backups is settings-sourced at the mirror in MIRRORED_STATE, so it re-points, not drops).
+    const dissolved = removeBackendAndMirrors(MIRRORED_STATE, mirroredDraft(), 'off-box');
+    expect(dissolved.backends.some((b) => b.name === 'off-box')).toBe(false);
+    expect(dissolved.backends.some((b) => b.type === 'mirror')).toBe(false);
+    expect(dissolved.categories.backups).toBe('backups-local');
+    // Multi-replica mirror: stripping one target keeps the mirror alive with the rest.
+    const twoTargets = setMirrorTargets(MIRRORED_STATE, mirroredDraft(), 'backups-local', ['off-box', 'uploads-local']);
+    const survived = removeBackendAndMirrors(MIRRORED_STATE, twoTargets, 'off-box');
+    const mirror = survived.backends.find((b) => b.type === 'mirror')!;
+    expect(mirror.options).toEqual({ primary: 'backups-local', replicas: ['uploads-local'] });
+    expect(survived.categories.backups).toBe('mirror'); // still routed via the surviving mirror
+  });
+
   it('FE-ADMIN-STORM-014: primaryNameOf maps mirror names (draft or state) to their primary; others pass through', () => {
     expect(primaryNameOf(MIRRORED_STATE, mirroredDraft(), 'mirror')).toBe('backups-local');
     expect(primaryNameOf(MIRRORED_STATE, { backends: [], categories: {} }, 'mirror')).toBe('backups-local'); // state fallback

client/src/components/Admin/storage/storageModel.ts

@@ -246,12 +246,40 @@ export function renameBackendRefs(draft: StorageConfig, oldName: string, newName
   }
 }
 
-/** Remove a backend AND every mirror wrapping it as primary (they would dangle). */
-export function removeBackendAndMirrors(draft: StorageConfig, name: string): StorageConfig {
-  return {
-    ...draft,
-    backends: draft.backends.filter((b) => b.name !== name && !(isMirror(b) && b.options.primary === name)),
+/**
+ * Remove a backend, every mirror wrapping it as primary, and every replica
+ * reference to it in the remaining mirrors — a mirror stripped of its last
+ * replica dissolves (with the same category re-pointing as an explicit
+ * dissolve), so the draft never carries a phantom reference the composer
+ * cannot render or repair.
+ */
+export function removeBackendAndMirrors(
+  state: StorageAdminState,
+  draft: StorageConfig,
+  name: string,
+): StorageConfig {
+  const stripped = draft.backends
+    .filter((b) => b.name !== name && !(isMirror(b) && b.options.primary === name))
+    .map((b) =>
+      isMirror(b) && b.options.replicas.includes(name)
+        ? { ...b, options: { ...b.options, replicas: b.options.replicas.filter((r) => r !== name) } }
+        : b,
+    )
+  let next: StorageConfig = { ...draft, backends: stripped }
+  for (const mirror of stripped.filter(isMirror)) {
+    if (mirror.options.replicas.length > 0) continue
+    if (adoptedMirrorFor(next, mirror.options.primary)?.name === mirror.name) {
+      next = setMirrorTargets(state, next, mirror.options.primary, [])
+    } else {
+      // A degenerate duplicate stripped empty: drop it and re-point its categories.
+      const categories = { ...next.categories }
+      for (const category of STORAGE_CATEGORIES) {
+        if (categories[category] === mirror.name) categories[category] = mirror.options.primary
+      }
+      next = { backends: next.backends.filter((b) => b.name !== mirror.name), categories }
+    }
   }
+  return next
 }
 
 /** Primaries whose mirrors use the named backend as a replica — pre-check copy stays in primary names. */

client/src/mobile/screens/admin/MAdminStoragePanel.tsx

@@ -355,6 +355,8 @@ export default function MAdminStoragePanel(): React.ReactElement {
           {rows.map((row) => {
             const resultKey = row.mirrorName ?? row.name
             const result = admin.testResults[resultKey]
+            // row.mirrorName only exists when foldBackends adopted a draft mirror
+            // for this row, so the draft lookup below cannot miss.
             const testCandidate = row.mirrorName
               ? draft.backends.find((b) => b.name === row.mirrorName)!
               : row.backend
@@ -575,7 +577,7 @@ export default function MAdminStoragePanel(): React.ReactElement {
             admin.setDraft(
               confirmRemove.degenerate
                 ? removeBackend(draft, confirmRemove.name)
-                : removeBackendAndMirrors(draft, confirmRemove.name),
+                : removeBackendAndMirrors(state, draft, confirmRemove.name),
             )
           }
           setConfirmRemove(null)