refactor: use LogViewer in AgentInstance page

Replace custom log entry rendering (MonoText, Badge, per-entry HTML) with
the LogViewer composite component. Map mock data to LogEntry interface,
remove formatLogTime helper, and clean up unused CSS classes and imports
(Card, CodeBlock, ProgressBar, sectionHeaderRow, sectionTitle, fdRow).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

src/pages/AgentInstance/AgentInstance.module.css

@@ -51,20 +51,6 @@
   font-family: var(--font-mono);
 }
 
-/* Section header — matches /agents */
-.sectionHeaderRow {
-  display: flex;
-  align-items: center;
-  gap: 8px;
-  margin-bottom: 12px;
-}
-
-.sectionTitle {
-  font-size: 13px;
-  font-weight: 600;
-  color: var(--text-primary);
-}
-
 /* Charts 3x2 grid */
 .chartsGrid {
   display: grid;
@@ -125,12 +111,6 @@
   font-weight: 500;
 }
 
-.fdRow {
-  display: flex;
-  align-items: center;
-  gap: 8px;
-}
-
 /* Log + Timeline side by side */
 .bottomRow {
   display: grid;
@@ -155,52 +135,7 @@
   border-bottom: 1px solid var(--border-subtle);
 }
 
-.logEntries {
-  max-height: 360px;
-  overflow-y: auto;
-  font-size: 11px;
-}
-
-.logEntry {
-  display: flex;
-  align-items: flex-start;
-  gap: 8px;
-  padding: 5px 16px;
-  border-bottom: 1px solid var(--border-subtle);
-  font-family: var(--font-mono);
-  transition: background 0.1s;
-}
-
-.logEntry:hover {
-  background: var(--bg-hover);
-}
-
-.logEntry:last-child {
-  border-bottom: none;
-}
-
-.logTime {
-  flex-shrink: 0;
-  color: var(--text-muted);
-  min-width: 60px;
-}
-
-.logLogger {
-  flex-shrink: 0;
-  color: var(--text-faint);
-  max-width: 220px;
-  overflow: hidden;
-  text-overflow: ellipsis;
-  white-space: nowrap;
-}
-
-.logMsg {
-  color: var(--text-primary);
-  font-family: var(--font-mono);
-  font-size: 11px;
-  word-break: break-word;
-}
-
+/* Empty state (shared) */
 .logEmpty {
   padding: 24px;
   text-align: center;