feat(P2.2c): show per-user custom libs in the Library Manager + autocomplete

The Library Manager Installed tab + the velxio.json add-autocomplete now merge
the user's per-user custom uploads (getCustomLibraries -> GET /api/pro/libraries/
custom) with the shared global index list, so users can see and reuse their own
uploads (which live in the per-user store, not the global list). A custom lib's
button removes it via the per-user delete endpoint (not arduino-cli uninstall,
which would not find it). Degrades to [] for OSS/anon.

frontend/src/components/simulator/LibraryManagerModal.tsx

@@ -4,6 +4,8 @@ import {
   searchLibraries,
   installLibrary,
   getInstalledLibraries,
+  getCustomLibraries,
+  deleteCustomLibrary,
   uninstallLibrary,
 } from '../../services/libraryService';
 import type { ArduinoLibrary, InstalledLibrary } from '../../services/libraryService';
@@ -66,8 +68,16 @@ export const LibraryManagerModal: React.FC<LibraryManagerModalProps> = ({ isOpen
   const fetchInstalled = useCallback(async () => {
     setLoadingInstalled(true);
     try {
-      const libs = await getInstalledLibraries();
-      setInstalledLibraries(libs);
+      // P2.2c — the shared global list (index libs) PLUS the user's per-user
+      // custom uploads (which live in their per-user store, not the global
+      // list). Custom first so they're easy to find; de-duped by name.
+      const [libs, custom] = await Promise.all([getInstalledLibraries(), getCustomLibraries()]);
+      const customNames = new Set(custom.map((c) => (c.name || '').toLowerCase()));
+      const merged = [
+        ...custom,
+        ...libs.filter((l) => !customNames.has((l.library?.name || l.name || '').toLowerCase())),
+      ];
+      setInstalledLibraries(merged);
     } catch (e: unknown) {
       setStatusMsg({
         type: 'error',
@@ -166,6 +176,25 @@ export const LibraryManagerModal: React.FC<LibraryManagerModalProps> = ({ isOpen
     }
   };
 
+  // P2.2c — a CUSTOM lib lives in the user's per-user store, not the shared
+  // arduino-cli dir, so removing it hits the per-user delete endpoint.
+  const handleRemoveCustom = async (libName: string) => {
+    setUninstallingLib(libName);
+    setStatusMsg(null);
+    try {
+      const result = await deleteCustomLibrary(libName);
+      if (result.success) {
+        setStatusMsg({ type: 'success', text: `Removed your custom "${libName}".` });
+        removeFromManifest(libName);
+        fetchInstalled();
+      } else {
+        setStatusMsg({ type: 'error', text: result.error || `Failed to remove "${libName}"` });
+      }
+    } finally {
+      setUninstallingLib(null);
+    }
+  };
+
   // ── Project manifest (velxio.json) editing ──────────────────────────────
   const declared = manifestLibs ?? [];
 
@@ -748,10 +777,19 @@ export const LibraryManagerModal: React.FC<LibraryManagerModalProps> = ({ isOpen
                     )}
                     <button
                       className="lib-uninstall-btn"
-                      onClick={() => handleUninstall(getInstalledName(lib))}
+                      onClick={() =>
+                        lib.custom
+                          ? handleRemoveCustom(getInstalledName(lib))
+                          : handleUninstall(getInstalledName(lib))
+                      }
                       disabled={uninstallingLib !== null}
+                      title={lib.custom ? 'Remove your custom upload' : 'Uninstall library'}
                     >
-                      {uninstallingLib === getInstalledName(lib) ? 'Uninstalling...' : 'UNINSTALL'}
+                      {uninstallingLib === getInstalledName(lib)
+                        ? 'Removing...'
+                        : lib.custom
+                          ? 'Remove'
+                          : 'UNINSTALL'}
                     </button>
                   </div>
                 </div>

frontend/src/services/libraryService.ts

@@ -32,6 +32,8 @@ export interface InstalledLibrary {
   version?: string;
   author?: string;
   sentence?: string;
+  /** P2.2c — true for the user's own per-user custom uploads (vs shared index libs). */
+  custom?: boolean;
 }
 
 export async function searchLibraries(query: string): Promise<ArduinoLibrary[]> {
@@ -74,6 +76,42 @@ export async function getInstalledLibraries(): Promise<InstalledLibrary[]> {
   return data.libraries || [];
 }
 
+/**
+ * P2.2c — the signed-in user's per-user CUSTOM libraries (uploaded .zip),
+ * which live in their per-user store, not the shared global list. Merged into
+ * the Installed view + velxio.json autocomplete so they can see and reuse their
+ * uploads. Returns [] when unauthenticated or no pro overlay (401/404).
+ */
+export async function getCustomLibraries(): Promise<InstalledLibrary[]> {
+  try {
+    const res = await fetch('/api/pro/libraries/custom', { credentials: 'include' });
+    if (!res.ok) return [];
+    const data = await res.json();
+    return Array.isArray(data) ? data : [];
+  } catch {
+    return [];
+  }
+}
+
+/** P2.2c — remove one of the user's own custom uploads (per-user store). */
+export async function deleteCustomLibrary(
+  name: string,
+): Promise<{ success: boolean; error?: string }> {
+  try {
+    const res = await fetch(`/api/pro/libraries/custom/${encodeURIComponent(name)}`, {
+      method: 'DELETE',
+      credentials: 'include',
+    });
+    if (!res.ok) {
+      const err = await res.json().catch(() => ({ detail: 'Failed to remove' }));
+      return { success: false, error: err.detail || 'Failed to remove' };
+    }
+    return { success: true };
+  } catch (e) {
+    return { success: false, error: e instanceof Error ? e.message : 'network error' };
+  }
+}
+
 /**
  * Resolve a library name to "Name@X.Y.Z" using arduino-cli lib search.
  * Returns null if the library is not found in the index.