Fix coverage with several contract classes; table annotation and file path checks; clean task dir on write

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_014aUaQeLnwbb1zTpN7kHeat

tasks_gen/eval/G0118/seed/if_canteen_plan.intf.abap

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+INTERFACE {{p}}if_canteen_plan PUBLIC.
+  TYPES ty_ingredient TYPE c LENGTH 10.
+  TYPES ty_quantity TYPE p LENGTH 13 DECIMALS 3.
+
+  TYPES:
+    BEGIN OF ty_order,
+      ingredient TYPE ty_ingredient,
+      quantity   TYPE ty_quantity,
+    END OF ty_order.
+  TYPES tt_order TYPE STANDARD TABLE OF ty_order WITH EMPTY KEY.
+
+  TYPES:
+    BEGIN OF ty_master,
+      ingredient TYPE ty_ingredient,
+      pack_size  TYPE ty_quantity,
+    END OF ty_master.
+  TYPES tt_master TYPE STANDARD TABLE OF ty_master WITH EMPTY KEY.
+
+  TYPES:
+    BEGIN OF ty_pack,
+      ingredient TYPE ty_ingredient,
+      packs      TYPE i,
+    END OF ty_pack.
+  TYPES tt_pack TYPE STANDARD TABLE OF ty_pack WITH EMPTY KEY.
+
+  TYPES tt_ingredient TYPE STANDARD TABLE OF ty_ingredient WITH EMPTY KEY.
+
+  METHODS merge_orders
+    IMPORTING it_orders_a      TYPE tt_order
+              it_orders_b      TYPE tt_order
+    RETURNING VALUE(rt_demand) TYPE tt_order.
+
+  METHODS pack_requirement
+    IMPORTING it_demand       TYPE tt_order
+              it_catalogue    TYPE tt_master
+    RETURNING VALUE(rt_packs) TYPE tt_pack.
+
+  METHODS missing_ingredients
+    IMPORTING it_demand        TYPE tt_order
+              it_catalogue     TYPE tt_master
+    RETURNING VALUE(rt_missing) TYPE tt_ingredient.
+ENDINTERFACE.