Adds the workshop-side counterpart to Stage 11B's intake form: a tracking workspace filtered by fulfillment stage, an auditable timeline of stage changes, and inventory deduction on completion. Closes audit finding P2.2; Stage 11 is complete.
Domain: FulfillmentEvent (append-only transition record with operator notes and a malformed-line-tolerant wire format), MaterialUsage, MaterialConsumptionPort + MaterialDeductionResult. Order gains fulfillmentHistory, materialUsage, derived stage accessors, and withFulfillmentEvent(). All existing fields, defaults, and copyWith semantics preserved.
Data: advanceFulfillmentStatus() records an event with an optional note and injectable clock; recordMaterialUsage() added. WooCommerce round-trips both through _kc_ meta keys, skipping malformed lines and never blanking remote values.
Application/presentation: AdvanceFulfillment, CompleteCustomOrder, CustomOrderTrackingController, CustomOrderTrackingPage, FulfillmentTimeline, showAdvanceStageDialog. Illegal transitions surface the domain rejection reason verbatim.
Architecture: inventory deduction crosses the feature boundary through an outbound port, not a package dependency. feature_orders still has no dependency on feature_inventory; each app supplies InventoryMaterialConsumptionAdapter. Completion advances first and deducts second, so a rejected transition can never decrement stock, and a deduction failure warns rather than failing the commission.
Tests: 329 new (293 feature_orders, 22 kell_mobile, 14 kell_web). 1085/1085 feature_orders, 109/109 kell_mobile, 81/81 kell_web. dart analyze --fatal-infos clean.
Mike Kell