Add matrix-group display for monthly/quarterly time-series fields in Stage 5

types/form.ts

@@ -91,6 +91,39 @@ export interface FieldConfig {
   optionGroupId?: number;
 }
 
+/**
+ * A repeating group of fields that share period axes — e.g. monthly sales
+ * targets across M1..M12, or quarterly margin across Q1..Q4. Rendered as a
+ * compact HTML table: rows are metrics, columns are periods.
+ *
+ * Underlying data flow is unchanged: each cell is still a regular form
+ * field (registered with react-hook-form, mapped to its own Civi custom
+ * field). The matrix is purely a display reorganization. Fields referenced
+ * in a matrix are skipped from the section's main per-field grid so they
+ * don't render twice.
+ */
+export interface MatrixGroupConfig {
+  /** Unique id within the section. */
+  id: string;
+  /** Heading shown above the table. */
+  label: string;
+  /** Optional intro paragraph below the heading. */
+  intro?: string;
+  /** Period columns, in left-to-right order. */
+  cols: Array<{ key: string; label: string }>;
+  /**
+   * Metric rows. `fields` is an array of form-side field names (the same
+   * `name` used in FieldConfig), one per column, in `cols` order.
+   * `type` controls the input rendering for this row's cells (currency,
+   * percent, number, etc).
+   */
+  rows: Array<{
+    label: string;
+    type: FieldType;
+    fields: string[];
+  }>;
+}
+
 export interface StageSectionConfig {
   /** Stage rank, 0..5. Used by the conditional engine and the accordion. */
   rank: number;
@@ -107,6 +140,12 @@ export interface StageSectionConfig {
    */
   visibleWhen?: VisibilityRule;
   fields: FieldConfig[];
+  /**
+   * Matrix groups rendered above the per-field grid. Fields referenced in
+   * any matrix are excluded from the per-field grid (so a Y1 monthly sales
+   * target doesn't appear both in the table and as a standalone field).
+   */
+  matrixGroups?: MatrixGroupConfig[];
 }
 
 export interface FormConfig {