docs: record the sorter's default (non-provenance) mode

- docs/SORTING.md: the extraction section now shows the default sort command (no --provenance) and presents --provenance as an optional mode.
- AGENTS.md 7: note that sorting runs in the default mode and that mixing the two modes creates duplicate placements.
Docs-only change; no code touched.

docs/SORTING.md

@@ -119,12 +119,17 @@ plan/apply-only):
   password archives, disk full) are moved to `<out>/.broken/` and the run
   continues; re-runs skip already-extracted destinations.
 - `<out>/extract_manifest.jsonl` records `{archive, dest, unit}` per
-  extraction. The sorter's `--provenance` flag reads it: all files inside
-  an extraction directory are classified **once under the archive's
-  name** (a loose `Backpack.stl` alone is noise; under
-  `The Twin Lance/` it belongs to that unit) and placed together, keeping
-  the archive's inner directory structure:
+  extraction. By **default the sorter classifies each file on its own
+  name**; the optional `--provenance <manifest>` mode instead classifies
+  each extraction directory **once under the archive's name** (a loose
+  `Backpack.stl` alone is noise; under `The Twin Lance/` it belongs to
+  that unit) and keeps the archive's inner directory structure. The live
+  library uses the default (non-provenance) mode:
 
+      # default — what Warhammer_Library_Live uses
+      dlphelper sorter <extracted_root> --library <lib> --apply
+
+      # optional provenance mode (whole extraction dirs as units)
       dlphelper sorter <extracted_root> --library <lib> \
           --provenance <extracted_root>/extract_manifest.jsonl --apply