feat(rates): multi-tier distance band entry in last-mile rate form

- tierList field type in rule-engine form dialog (add/remove rows,
  overlap + open-ended validation, From km auto-continues)
- create submits one rate row per tier sequentially
- editing a band row keeps the single From/To/value form

apps/edr-freight-web/backoffice/src/pages/ruleEngine/RuleEngineResourcePage.tsx

@@ -306,7 +306,34 @@ const RuleEngineResourcePage = () => {
 
   const formFields = useMemo(() => {
     if (!config) return [];
-    return config.formFields.map((field) => {
+    // Last-mile container bands: creating uses the multi-row tier list (one
+    // rate per tier); editing an existing band row keeps the single
+    // From/To/value fields (a rate row IS one band).
+    const bandFields = config.formFields.filter((field) => {
+      if (config.slug !== "rates") return true;
+      if (field.type === "tierList") return !editing;
+      if (editing) return true;
+      return field.name !== "minKm" && field.name !== "maxKm";
+    });
+    return bandFields.map((field) => {
+      // On create, the tier rows carry the per-band rate values — the single
+      // last-mile "Rate value" field then only applies to bulk mode.
+      if (
+        config.slug === "rates" &&
+        !editing &&
+        field.name === "rateValue" &&
+        field.showWhen?.field === "appliesTo" &&
+        field.showWhen.equals.includes("LAST_MILE")
+      ) {
+        return {
+          ...field,
+          showWhen: undefined,
+          showIf: (values: Record<string, unknown>) =>
+            values.appliesTo === "LAST_MILE" && values.lastMileMode === "BULK",
+        };
+      }
+      return field;
+    }).map((field) => {
       if (isPriorityRules && field.name === "minWagonCount") {
         return {
           ...field,
@@ -624,6 +651,31 @@ const RuleEngineResourcePage = () => {
         );
         return;
       }
+      // Container-mode create: the tier list becomes one rate row per tier,
+      // created sequentially so an overlap/duplicate rejection stops the batch
+      // with its own toast instead of half-failing in parallel.
+      const tiers = (
+        payload as {
+          tiers?: Array<{ minKm: number; maxKm: number | null; rateValue: number }>;
+        }
+      ).tiers;
+      if (!editing?.id && Array.isArray(tiers)) {
+        const { tiers: _omitted, ...base } = payload as Record<string, unknown>;
+        void _omitted;
+        void (async () => {
+          try {
+            for (const tier of tiers) {
+              await create.mutateAsync({ ...base, ...tier });
+            }
+            setFormOpen(false);
+            setEditing(null);
+          } catch {
+            // The create mutation already toasted the failure; keep the dialog
+            // open so the admin can fix the tier set and retry.
+          }
+        })();
+        return;
+      }
     } else if (isPriorityRules) {
       // Label is required by the backend but hidden in the UI for now.
       payload = { ...values, label: String(Date.now()) };

apps/edr-freight-web/backoffice/src/pages/ruleEngine/config/resources.ts

@@ -17,7 +17,7 @@ export type ColumnFormat =
   | "entityLabel"
   | "rateLabel";
 
-export type FormFieldType = "text" | "number" | "boolean" | "date" | "email" | "select" | "multiselect" | "textarea" | "radio";
+export type FormFieldType = "text" | "number" | "boolean" | "date" | "email" | "select" | "multiselect" | "textarea" | "radio" | "tierList";
 
 export interface ResourceColumn {
   id: string;
@@ -1022,6 +1022,19 @@ export const RULE_ENGINE_RESOURCES: RuleEngineResourceConfig[] = [
         showWhen: { field: "appliesTo", equals: ["LAST_MILE"] },
         getInitialValue: (record) => String(record.currency ?? "ETB"),
       },
+      // ── Distance tiers (create only — the page swaps this for the single
+      // From/To/value fields when editing an existing band row). Each tier
+      // becomes its own rate row, so every band keeps edit/delete/approval. ──
+      {
+        name: "tiers",
+        label: "Distance tiers",
+        type: "tierList",
+        required: true,
+        description:
+          "One rate per distance range. To km is exclusive (0–30 then 30+); leave the last tier's To km empty for no upper limit.",
+        showIf: (v) =>
+          v.appliesTo === "LAST_MILE" && v.lastMileMode === "CONTAINER",
+      },
       // ── Container type — Container freight, container-kind intercity, and
       // the empty-container return surcharge (20ft vs 40ft price differently) ─
       {