T8.6 - D6: the material list uploads the way the location list does

CR-013 accepted free text because the master workbook never arrived; the
Aug 18 call was the CR-005 call again - build the upload path now.

THE component, extracted: T5.4's paste-or-file machinery (file read in the
browser, ONE parser on the server; dry-run check; a report naming every
rejected row with its source line; an editable list that deactivates rather
than deletes) moved from the location-specific functions into
html/wp-list-import.js. The location list and the new material list are both
instances of it - the done-when's "against the same component, not beside it"
made literally true. The loc* names survive as thin delegates because row
handlers, step entry and the probes call them; locations_check re-pointed its
fetch-count assertion to where the fetches now live and still demands every
read and write reach the server.

The material list itself: description, unit, optional code - one new table
(Alembic a1b8c6d4e2f9, additive), GET/import/POST/PATCH routes on the CR-005
pattern, deactivate-never-delete, reactivation reuses the same row so nothing
referencing it orphans. The sample rows are obviously fake (SAMPLE-EMT-075).
NO inventory, price, stock or warehouse field anywhere - the probe walks the
model's columns by regex. The wizard hosts it on step 11 beside the location
list, optional by design: a project with no list still raises free-text
requests (T8.5 wires that).

Parser bug caught by the probe's first run: strip(',;') ate a LEADING comma,
so ',FT' - an empty description - was accepted as a material named FT.
rstrip only, now; the empty first column is rejected with its line number.

Verification (each probe run alone): NEW tests/materials_check.py 17/17.
Regression: locations_check 58/58 through the shared component.

Items: D6

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

docs/reference/file-map.md

@@ -292,6 +292,7 @@ Wave 8 adds these:
 ```bash
 python tests/kitting_check.py        # CR-009/010/012 - statuses, owner, delivery 26 checks
 python tests/kitting_notify_check.py # CR-011 - kitting mail, coalesced, gated    17 checks
+python tests/materials_check.py      # D6 - material list, the CR-005 pattern     17 checks
 ```
 
 **Three probes were re-pointed at `T7.1`.** `sections_check.py` 5b drove the live