feat: 添加算术验证码与字符验证码处理能力

新增算术验证码解析、字符清洗能力及测试文件，注册OCR_CalculationCode和OCR_CommonEnglishNumbersCode两个新能力，补充验证码处理逻辑

packages/rpa-core/src/capabilities/captcha-caps.test.ts

@@ -0,0 +1,56 @@
+import { existsSync } from "node:fs";
+import { describe, expect, it } from "vitest";
+import { getHandler } from "../engine/registry";
+import type { CatalogComponent, FlowNode } from "../types";
+import type { RunContext } from "../engine/types";
+import "./remaining-core";
+import "./captcha-caps"; // last-wins：覆盖 remaining-core 的通用实现
+import { cleanCodeText, parseCalculation } from "./captcha-caps";
+
+const ctx = { signal: new AbortController().signal, log: () => {}, vars: {}, evidenceDir: "D:/office-test2/ocr-test" } as unknown as RunContext;
+const node: FlowNode = { id: "smoke", componentId: "smoke", position: { x: 0, y: 0 }, values: {}, options: {} };
+
+describe("parseCalculation 解析层（纯逻辑）", () => {
+  it("基础四则与等号问号", () => {
+    expect(parseCalculation("3+5=?")).toEqual({ expression: "3+5", result: 8 });
+  });
+  it("x/X/* 归一为乘", () => {
+    expect(parseCalculation("6x4=?")!.result).toBe(24);
+    expect(parseCalculation("9X9=?")!.result).toBe(81);
+  });
+  it("全角与杂字符", () => {
+    expect(parseCalculation("１２＋７＝？")!.result).toBe(19);
+  });
+  it("长破折号/Unicode 减号", () => {
+    expect(parseCalculation("12—7")!.result).toBe(5);
+  });
+  it("除法整除与小数", () => {
+    expect(parseCalculation("8/2")!.result).toBe(4);
+    expect(parseCalculation("7/2")!.result).toBe(3.5);
+  });
+  it("无算式返回 null", () => {
+    expect(parseCalculation("ab12cd")).toBeNull();
+  });
+  it("字符验证码清洗", () => {
+    expect(cleanCodeText("a b 7 X ? = ")).toBe("ab7X");
+  });
+});
+
+describe.skipIf(!existsSync("D:/office-test2/ocr-test/captcha_0_3p5_q.png"))("OCR_CalculationCode 端到端（真实模型）", () => {
+  const cases: Array<[string, string]> = [
+    ["captcha_0_3p5_q", "8"],
+    ["captcha_1_12m7_q", "5"],
+    ["captcha_2_6t4_q", "24"],
+    ["captcha_3_15p28_q", "43"],
+    ["captcha_4_9t9_q", "81"],
+  ];
+  for (const [file, expected] of cases) {
+    it(`${file} -> ${expected}`, async () => {
+      const handler = getHandler("OCR_CalculationCode");
+      expect(handler).toBeTruthy();
+      const out = await handler!(ctx, node, { path: `D:/office-test2/ocr-test/${file}.png` }, {} as CatalogComponent);
+      console.log(`[${file}]`, String(out));
+      expect(String(out)).toBe(expected);
+    }, 300000);
+  }
+});