refactor(daemon): consolidate local-only sync functions to reduce duplication (bd-73u)

Extract performExport() and performAutoImport() shared implementations:
- createExportFunc() and createLocalExportFunc() now use performExport()
  with skipGit parameter
- createAutoImportFunc() and createLocalAutoImportFunc() now use performAutoImport()
  with skipGit parameter
- createLocalSyncFunc() kept as-is (different flow from createSyncFunc)

Reduces daemon_sync.go by 89 lines (1003 -> 914) while maintaining
identical behavior and test coverage.

All existing tests pass. New shared functions use conditional logic
to skip git operations when skipGit=true, eliminating the need for
separate implementations.

.beads/deletions.jsonl

@@ -1 +0,0 @@
-