feat: maintenance flows frontend foundation - types, API clients, sidebar, library filter

- Add maintenance.ts types: TargetEntry, TargetList, MaintenanceSchedule, BatchLaunch
- Add targetListsApi and maintenanceSchedulesApi/batchLaunchApi clients
- Extend TreeType union with 'maintenance' in tree.ts
- Update getTreeNavigatePath/getTreeEditorPath in routing.ts for maintenance
- Sidebar: track maintenance count and add Maintenance sub-nav item
- TreeLibraryPage: add maintenance to typeFilter state, URL sync, and tab buttons
- TreeGridView, TreeListView, TreeTableView: add amber Wrench maintenance badge

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

frontend/src/components/library/TreeGridView.tsx

@@ -1,5 +1,5 @@
 import { Link } from 'react-router-dom'
-import { Pencil, Globe, Lock, Trash2, GitBranch, FileText } from 'lucide-react'
+import { Pencil, Globe, Lock, Trash2, GitBranch, FileText, Wrench } from 'lucide-react'
 import type { TreeListItem } from '@/types'
 import { TagBadges } from '@/components/common/TagBadges'
 import { AddToFolderMenu } from './AddToFolderMenu'
@@ -41,6 +41,12 @@ export function TreeGridView({
                   Draft
                 </span>
               )}
+              {tree.tree_type === 'maintenance' && (
+                <span className="inline-flex items-center gap-1 rounded-full border border-amber-500/30 bg-amber-500/10 px-2 py-0.5 font-label text-[0.625rem] uppercase tracking-wide text-amber-400">
+                  <Wrench className="h-3 w-3" />
+                  Maintenance
+                </span>
+              )}
             </div>
             <div className="flex items-center gap-2">
               {tree.is_public ? (

frontend/src/components/library/TreeListView.tsx

@@ -1,5 +1,5 @@
 import { Link } from 'react-router-dom'
-import { Pencil, Globe, Lock, GitBranch, FileText, Trash2 } from 'lucide-react'
+import { Pencil, Globe, Lock, GitBranch, FileText, Trash2, Wrench } from 'lucide-react'
 import type { TreeListItem } from '@/types'
 import { TagBadges } from '@/components/common/TagBadges'
 import { AddToFolderMenu } from './AddToFolderMenu'
@@ -42,6 +42,12 @@ export function TreeListView({
                   Draft
                 </span>
               )}
+              {tree.tree_type === 'maintenance' && (
+                <span className="inline-flex items-center gap-1 rounded-full border border-amber-500/30 bg-amber-500/10 px-2 py-0.5 font-label text-[0.625rem] uppercase tracking-wide text-amber-400 flex-shrink-0">
+                  <Wrench className="h-3 w-3" />
+                  Maintenance
+                </span>
+              )}
               {tree.is_public ? (
                 <span title="Public tree">
                   <Globe className="h-3.5 w-3.5 text-muted-foreground flex-shrink-0" />

frontend/src/components/library/TreeTableView.tsx

@@ -1,6 +1,6 @@
 import { useState } from 'react'
 import { Link } from 'react-router-dom'
-import { Pencil, Globe, Lock, ChevronUp, ChevronDown, GitBranch, FileText, Trash2 } from 'lucide-react'
+import { Pencil, Globe, Lock, ChevronUp, ChevronDown, GitBranch, FileText, Trash2, Wrench } from 'lucide-react'
 import type { TreeListItem } from '@/types'
 import { TagBadges } from '@/components/common/TagBadges'
 import { AddToFolderMenu } from './AddToFolderMenu'
@@ -144,6 +144,12 @@ export function TreeTableView({
                       Draft
                     </span>
                   )}
+                  {tree.tree_type === 'maintenance' && (
+                    <span className="inline-flex items-center gap-1 rounded-full border border-amber-500/30 bg-amber-500/10 px-2 py-0.5 font-label text-[0.625rem] uppercase tracking-wide text-amber-400 flex-shrink-0">
+                      <Wrench className="h-3 w-3" />
+                      Maintenance
+                    </span>
+                  )}
                   {tree.is_public ? (
                     <span title="Public tree">
                       <Globe className="h-3.5 w-3.5 text-muted-foreground flex-shrink-0" />