feat(sp6): Lane component with multi-select

src/components/inbox/Lane.test.tsx

@@ -0,0 +1,58 @@
+// @vitest-environment happy-dom
+import { afterEach, describe, expect, it, vi } from "vitest";
+import { cleanup, render, screen, fireEvent } from "@testing-library/react";
+import { Lane } from "./Lane";
+import type { InboxClaimRow } from "@/lib/inbox-api";
+
+afterEach(() => cleanup());
+
+const sampleRows: InboxClaimRow[] = [
+  {
+    id: "CLP-1",
+    kind: "claim",
+    patient_control_number: "PCN-1",
+    charge_amount: 100,
+    payer_id: "PAYER-A",
+    provider_npi: "1234567890",
+    state: "rejected",
+    rejection_reason: "R69",
+    rejected_at: "2026-06-20T09:00:00Z",
+    service_date_from: null,
+    score: null,
+    score_tier: null,
+    score_breakdown: null,
+  },
+];
+
+describe("Lane", () => {
+  it("renders the lane name and row count", () => {
+    const { container } = render(
+      <Lane name="REJECTED" accent="oxblood" rows={sampleRows} onRowClick={() => {}} />,
+    );
+    expect(container.textContent).toContain("REJECTED");
+    expect(container.textContent).toContain("1");
+  });
+
+  it("renders an empty state when no rows", () => {
+    const { container } = render(
+      <Lane name="DONE" accent="muted" rows={[]} onRowClick={() => {}} />,
+    );
+    expect(container.textContent).toMatch(/nothing here/i);
+  });
+
+  it("supports multi-select via row checkbox toggle", () => {
+    const onSelectionChange = vi.fn();
+    render(
+      <Lane
+        name="REJECTED"
+        accent="oxblood"
+        rows={sampleRows}
+        onRowClick={() => {}}
+        onSelectionChange={onSelectionChange}
+      />,
+    );
+    const cb = screen.getByRole("checkbox");
+    fireEvent.click(cb);
+    expect(onSelectionChange).toHaveBeenCalled();
+  });
+});

src/components/inbox/Lane.tsx

@@ -0,0 +1,101 @@
+import { useState } from "react";
+import { InboxRow, type Accent } from "./InboxRow";
+import type { InboxClaimRow, InboxCandidateRow } from "@/lib/inbox-api";
+
+export type LaneRow = InboxClaimRow | InboxCandidateRow;
+
+export function Lane({
+  name,
+  accent,
+  rows,
+  onRowClick,
+  onSelectionChange,
+}: {
+  name: string;
+  accent: Accent;
+  rows: LaneRow[];
+  onRowClick: (row: LaneRow) => void;
+  onSelectionChange?: (ids: string[]) => void;
+}) {
+  const [selected, setSelected] = useState<Set<string>>(new Set());
+
+  function rowId(row: LaneRow): string {
+    return row.kind === "remit" ? (row as InboxCandidateRow).payer_claim_control_number : row.id;
+  }
+
+  function toggle(id: string) {
+    const next = new Set(selected);
+    if (next.has(id)) next.delete(id);
+    else next.add(id);
+    setSelected(next);
+    onSelectionChange?.(Array.from(next));
+  }
+
+  return (
+    <section
+      className="flex-1 min-w-[280px] flex flex-col"
+      style={{
+        background: "var(--tt-bg-elev)",
+        border: "1px solid var(--tt-bg)",
+        borderRadius: 4,
+      }}
+      data-lane={name.toLowerCase()}
+    >
+      <header
+        className="px-3 py-2 flex items-baseline justify-between"
+        style={{ borderBottom: "1px solid var(--tt-bg)" }}
+      >
+        <h2
+          className="font-mono uppercase tracking-widest"
+          style={{ color: "var(--tt-ink)", fontSize: 11, letterSpacing: "0.12em" }}
+        >
+          {name}
+        </h2>
+        <span
+          className="font-mono tabular-nums"
+          style={{ color: "var(--tt-amber)", fontSize: 18 }}
+        >
+          {rows.length}
+        </span>
+      </header>
+
+      {rows.length === 0 ? (
+        <p
+          className="p-4 font-mono"
+          style={{ color: "var(--tt-muted)", fontSize: 11 }}
+        >
+          Nothing here.
+        </p>
+      ) : (
+        <div className="w-full" style={{ fontSize: 12 }}>
+          {rows.map((row) => {
+            const id = rowId(row);
+            return (
+              <div
+                key={id}
+                className="flex items-stretch"
+                style={{ borderBottom: "1px solid var(--tt-bg)" }}
+              >
+                <label
+                  className="flex items-center justify-center"
+                  style={{ width: 28, padding: "0 4px 0 8px" }}
+                >
+                  <input
+                    type="checkbox"
+                    aria-label={`Select ${id}`}
+                    checked={selected.has(id)}
+                    onChange={() => toggle(id)}
+                    onClick={(e) => e.stopPropagation()}
+                  />
+                </label>
+                <div style={{ width: "100%" }}>
+                  <InboxRow row={row} accent={accent} onClick={() => onRowClick(row)} />
+                </div>
+              </div>
+            );
+          })}
+        </div>
+      )}
+    </section>
+  );
+}