feat(watcher): add Flip transfer receipt provider

Match no-reply@flip.id transfer success mail (direct or forwarded), parse stacked Nominal/ID Transaksi fields, and map spendings with source=flip.

Co-authored-by: Cursor <cursoragent@cursor.com>

apps/watcher/test/match.test.js

@@ -12,6 +12,8 @@ import {
   briQrisForwardedBody,
   briTransferDirectBody,
   briTransferForwardedBody,
+  flipDirectBody,
+  flipForwardedBody,
   grabBody,
   grabForwardedBody,
   livinDirectBody,
@@ -223,6 +225,32 @@ describe("matchRule", () => {
     assert.equal(result.pass.rule.kind, "tokopedia.order.completed");
   });
 
+  it("matches direct Flip transfer", async () => {
+    const result = await matchRule({
+      messageId: "flip-direct",
+      log: silentLog,
+      message: {
+        from: "Flip <no-reply@flip.id>",
+        subject: "Transfer ke Rwen Ibrahim berhasil",
+        body: flipDirectBody,
+      },
+    });
+    assert.equal(result.pass.rule.kind, "flip.transfer.success");
+  });
+
+  it("matches forwarded Flip transfer via original header", async () => {
+    const result = await matchRule({
+      messageId: "1a0c704164e0cd54",
+      log: silentLog,
+      message: {
+        from: "NSRB <nasyarobby@gmail.com>",
+        subject: "Fwd: Transfer ke Rwen Ibrahim berhasil",
+        body: flipForwardedBody,
+      },
+    });
+    assert.equal(result.pass.rule.kind, "flip.transfer.success");
+  });
+
   it("breaks on unknown from/subject", async () => {
     const result = await matchRule({
       messageId: "x",