feat: fix sync counters, polished activity rows, Files tab, new icon

- Fix SYNC_COMPLETED showing ↑0 ↓0 ✗0 when only deletions occurred: add ✕N
  for deleted files to the summary message (↑N ↓N ✕N ✗N format)
- Fix PairDetail Activity section showing raw "SYNC_STARTED" enum names and
  "remote" as a plain subtitle: replace dot-based EventRow with the same
  polished icon-bubble rows as the global Log tab
- Extract shared SyncEventRow composable + iconAndTint/label helpers to
  ui/shared/SyncEventRow.kt; both LogScreen and PairDetailScreen now use it
- Add Files tab (4th tab between Log and Accounts): folder browser showing
  all synced files per pair, grouped by subdirectory, with file-type icons,
  size, last-synced date, and a summary header (N files, total size)
- Add SyncFileStateDao.observeForPair() reactive Flow query for Files tab
- Completely redesign app icon: near-black radial gradient background with
  three bold directional arrows in an S-pattern (coral → silver → teal),
  each with gradient fills and tip-glow dots — entirely different from the
  typical circular sync-arrow style
- Bump version to 1.0.22 (build 23)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/src/main/kotlin/com/syncflow/domain/sync/SyncEngine.kt

@@ -46,7 +46,7 @@ class SyncEngine @Inject constructor(
                 else -> SyncStatus.SUCCESS
             }
             syncPairDao.updateSyncResult(pair.id, Instant.now(), finalStatus, result.conflicts)
-            logEvent(pair.id, SyncEventType.SYNC_COMPLETED, null, "↑${result.uploaded} ↓${result.downloaded} ✗${result.failedFiles}", result.bytesTransferred)
+            logEvent(pair.id, SyncEventType.SYNC_COMPLETED, null, "↑${result.uploaded} ↓${result.downloaded} ✕${result.deleted} ✗${result.failedFiles}", result.bytesTransferred)
             result
         } catch (e: Exception) {
             Timber.e(e, "Sync failed for pair ${pair.id}")