feat(ui): add Sources tab skeleton with data fetch

Adds Usage page tab that fetches /api/auth/usage/sources (or the
admin variant). Renders raw totals plus a placeholder key list;
real visualisations land in subsequent commits. Restructures the
existing tab button block so Models and Sources are visible to
non-admins (Users remains admin-only).

Refs: #9862
Signed-off-by: Ettore Di Giacinto <mudler@localai.io>

core/http/react-ui/src/pages/Usage.jsx

@@ -4,6 +4,7 @@ import { useTranslation } from 'react-i18next'
 import { useAuth } from '../context/AuthContext'
 import { apiUrl } from '../utils/basePath'
 import LoadingSpinner from '../components/LoadingSpinner'
+import SourcesTab from './Usage/SourcesTab'
 
 const PERIODS = [
   { key: 'day', label: 'Day' },
@@ -724,23 +725,27 @@ export default function Usage() {
             {p.label}
           </button>
         ))}
+        <div style={{ width: 1, height: 20, background: 'var(--color-border-subtle)', margin: '0 var(--spacing-xs)' }} />
+        <button
+          className={`btn btn-sm ${activeTab === 'models' ? 'btn-primary' : 'btn-secondary'}`}
+          onClick={() => setActiveTab('models')}
+        >
+          <i className="fas fa-cube" style={{ fontSize: '0.7rem' }} /> Models
+        </button>
         {isAdmin && (
-          <>
-            <div style={{ width: 1, height: 20, background: 'var(--color-border-subtle)', margin: '0 var(--spacing-xs)' }} />
-            <button
-              className={`btn btn-sm ${activeTab === 'models' ? 'btn-primary' : 'btn-secondary'}`}
-              onClick={() => setActiveTab('models')}
-            >
-              <i className="fas fa-cube" style={{ fontSize: '0.7rem' }} /> Models
-            </button>
-            <button
-              className={`btn btn-sm ${activeTab === 'users' ? 'btn-primary' : 'btn-secondary'}`}
-              onClick={() => setActiveTab('users')}
-            >
-              <i className="fas fa-users" style={{ fontSize: '0.7rem' }} /> Users
-            </button>
-          </>
+          <button
+            className={`btn btn-sm ${activeTab === 'users' ? 'btn-primary' : 'btn-secondary'}`}
+            onClick={() => setActiveTab('users')}
+          >
+            <i className="fas fa-users" style={{ fontSize: '0.7rem' }} /> Users
+          </button>
         )}
+        <button
+          className={`btn btn-sm ${activeTab === 'sources' ? 'btn-primary' : 'btn-secondary'}`}
+          onClick={() => setActiveTab('sources')}
+        >
+          <i className="fas fa-key" style={{ fontSize: '0.7rem' }} /> {t('usage.sources.tab')}
+        </button>
         <div style={{ flex: 1 }} />
         <button className="btn btn-secondary btn-sm" onClick={fetchUsage} disabled={loading} style={{ gap: 4 }}>
           <i className={`fas fa-rotate${loading ? ' fa-spin' : ''}`} /> Refresh
@@ -884,6 +889,10 @@ export default function Usage() {
               </div>
             )
           )}
+
+          {activeTab === 'sources' && (
+            <SourcesTab period={period} adminUserId={selectedUserId} />
+          )}
         </>
       )}
     </div>

core/http/react-ui/src/pages/Usage/SourcesTab.jsx

@@ -0,0 +1,150 @@
+import { useEffect, useState } from 'react'
+import { useTranslation } from 'react-i18next'
+import { usageApi } from '../../utils/api'
+import { useAuth } from '../../context/AuthContext'
+import LoadingSpinner from '../../components/LoadingSpinner'
+
+const EMPTY_DATA = {
+  buckets: [],
+  totals: { by_source: {}, by_key: [], grand_total: { tokens: 0, requests: 0 } },
+  truncated: false,
+}
+
+// SourcesTab fetches and renders per-source / per-API-key usage breakdown.
+// Task 9 ships a minimal skeleton (raw totals + key list) so the data path is
+// exercised end to end. Tasks 10 and 11 replace the placeholders with the
+// SourceMixRibbon, SourceTimeChart and SourcesTable visualisations.
+export default function SourcesTab({ period, adminUserId }) {
+  const { t } = useTranslation('admin')
+  const { isAdmin } = useAuth()
+
+  const [data, setData] = useState(EMPTY_DATA)
+  const [loading, setLoading] = useState(false)
+  const [error, setError] = useState(null)
+
+  // State held now even though Tasks 10/11 will use it visually.
+  const [selectedKey, setSelectedKey] = useState(null)
+  // eslint-disable-next-line no-unused-vars
+  const [search, setSearch] = useState('')
+  // eslint-disable-next-line no-unused-vars
+  const [sortKey, setSortKey] = useState('tokens')
+
+  useEffect(() => {
+    let cancelled = false
+    setLoading(true)
+    setError(null)
+    const p = isAdmin
+      ? usageApi.getAdminSources(period, adminUserId)
+      : usageApi.getMySources(period)
+    p
+      .then((d) => { if (!cancelled) setData(d || EMPTY_DATA) })
+      .catch((e) => { if (!cancelled) setError(e) })
+      .finally(() => { if (!cancelled) setLoading(false) })
+    return () => { cancelled = true }
+  }, [isAdmin, period, adminUserId])
+
+  const totals = data.totals || EMPTY_DATA.totals
+  const grandT = totals.grand_total || { tokens: 0, requests: 0 }
+  const truncated = data.truncated || false
+
+  const isEmpty = !loading && (grandT.tokens || 0) === 0 && (grandT.requests || 0) === 0
+
+  if (loading) {
+    return (
+      <div style={{ display: 'flex', justifyContent: 'center', padding: 'var(--spacing-xl)' }}>
+        <LoadingSpinner size="lg" />
+      </div>
+    )
+  }
+
+  if (error) {
+    return (
+      <div className="empty-state">
+        <div className="empty-state-icon"><i className="fas fa-triangle-exclamation" /></div>
+        <h2 className="empty-state-title">Failed to load</h2>
+        <p className="empty-state-text">{String(error.message || error)}</p>
+      </div>
+    )
+  }
+
+  if (isEmpty) {
+    return (
+      <div className="empty-state">
+        <div className="empty-state-icon"><i className="fas fa-key" /></div>
+        <h2 className="empty-state-title">{t('usage.sources.noTrafficShort')}</h2>
+        <p className="empty-state-text">{t('usage.sources.noKeysYet')}</p>
+      </div>
+    )
+  }
+
+  // Skeleton placeholders: Tasks 10 and 11 replace these with SourceMixRibbon,
+  // SourceTimeChart, and SourcesTable.
+  return (
+    <div style={{ display: 'flex', flexDirection: 'column', gap: 'var(--spacing-md)' }}>
+      <div className="card" style={{ padding: 'var(--spacing-md)' }}>
+        <div style={{
+          fontSize: '0.6875rem',
+          color: 'var(--color-text-muted)',
+          fontWeight: 500,
+          textTransform: 'uppercase',
+          letterSpacing: '0.03em',
+          marginBottom: 'var(--spacing-xs)',
+        }}>{t('usage.sources.mixTitle')}</div>
+        <pre style={{
+          fontSize: '0.75rem',
+          background: 'var(--color-bg-secondary)',
+          padding: 'var(--spacing-sm)',
+          borderRadius: 'var(--radius-sm)',
+          overflow: 'auto',
+          margin: 0,
+          fontFamily: 'var(--font-mono)',
+        }}>{JSON.stringify(totals.by_source, null, 2)}</pre>
+      </div>
+
+      <div className="card" style={{ padding: 'var(--spacing-md)' }}>
+        <div style={{
+          fontSize: '0.6875rem',
+          color: 'var(--color-text-muted)',
+          fontWeight: 500,
+          textTransform: 'uppercase',
+          letterSpacing: '0.03em',
+          marginBottom: 'var(--spacing-xs)',
+        }}>{t('usage.sources.topSources')}</div>
+        <ul style={{ listStyle: 'none', padding: 0, margin: 0 }}>
+          {(totals.by_key || []).map((k) => {
+            const isSelected = selectedKey === k.api_key_id
+            return (
+              <li
+                key={k.api_key_id}
+                onClick={() => setSelectedKey(isSelected ? null : k.api_key_id)}
+                style={{
+                  padding: 'var(--spacing-xs) var(--spacing-sm)',
+                  cursor: 'pointer',
+                  fontWeight: isSelected ? 600 : 400,
+                  fontSize: '0.8125rem',
+                  borderRadius: 'var(--radius-sm)',
+                  background: isSelected ? 'var(--color-bg-secondary)' : 'transparent',
+                  display: 'flex',
+                  alignItems: 'center',
+                  gap: 6,
+                }}
+              >
+                <i className="fas fa-key" style={{ color: 'var(--color-text-muted)', fontSize: '0.75rem' }} />
+                <span style={{ fontFamily: 'var(--font-mono)' }}>{k.api_key_name || k.api_key_id}</span>
+                <span style={{ color: 'var(--color-text-muted)', marginLeft: 'auto', fontFamily: 'var(--font-mono)' }}>
+                  {Number(k.tokens || 0).toLocaleString()}
+                </span>
+              </li>
+            )
+          })}
+        </ul>
+      </div>
+
+      {truncated && (
+        <div style={{ fontSize: '0.75rem', color: 'var(--color-warning)' }}>
+          {t('usage.sources.truncatedWarning')}
+        </div>
+      )}
+    </div>
+  )
+}