Refactor: Split up the two biggest files

- Tab operations (363 lines) → tab-operations.ts
- Rename flow (274 lines) → rename-flow.svelte.ts
- DualPaneExplorer: 2514 → 2284 lines
- FilePane: 1887 → 1667 lines

Author: vdavid

apps/desktop/coverage-allowlist.json

@@ -32,6 +32,9 @@
         "file-explorer/pane/FilePane.svelte": { "reason": "Tested in integration.test.ts, complex component" },
         "file-explorer/pane/MtpConnectionView.svelte": { "reason": "MTP connection UI, depends on Tauri APIs" },
         "file-explorer/pane/NetworkMountView.svelte": { "reason": "Network mount UI, depends on Tauri APIs" },
+        "file-explorer/pane/rename-flow.svelte.ts": {
+            "reason": "Extracted from FilePane, depends on Tauri commands and rename operations"
+        },
         "file-explorer/pane/selection-state.svelte.ts": {
             "reason": "Reactive selection state, tested via FilePane integration"
         },
@@ -166,6 +169,9 @@
         "file-explorer/tabs/TabBar.svelte": {
             "reason": "UI component, tab interactions tested via DualPaneExplorer integration"
         },
+        "file-explorer/pane/tab-operations.ts": {
+            "reason": "Extracted from DualPaneExplorer, depends on Tauri commands and confirmDialog"
+        },
         "tauri-commands/tab.ts": {
             "reason": "Tauri command wrappers, tested via integration"
         }

apps/desktop/src/lib/file-explorer/CLAUDE.md

@@ -116,7 +116,8 @@ Core explorer UI components:
 - **PaneResizer.svelte** — Drag handle between the two panes
 - **PermissionDeniedPane.svelte** — Shown when a directory can't be read
 - **selection-state.svelte.ts** — Reactive selection set (indices) with range/toggle helpers
-- **sorting-handlers.ts** / **transfer-operations.ts** — Pure logic extracted from DualPaneExplorer
+- **sorting-handlers.ts** / **transfer-operations.ts** / **tab-operations.ts** — Pure logic extracted from DualPaneExplorer
+- **rename-flow.svelte.ts** — Rename flow logic (validation, conflict/extension dialogs) extracted from FilePane
 
 ## Tabs (`tabs/`)