Add synthetic Bitwarden test exports

tests/fixtures/README.md

@@ -1,3 +1,14 @@
 # Synthetic fixtures
 
 Fixtures in this directory must contain fake credentials only. Never place a real Bitwarden export here.
+
+## Sample pair
+
+`sample-export-a.json` and `sample-export-b.json` are synthetic Bitwarden-style exports for manual testing. They intentionally include:
+
+- An exact login duplicate despite different item IDs, names, folders, favorite flags, casing, and `www.` URL formatting.
+- A likely duplicate with the same username and URL but different password, TOTP, notes, and custom fields; B has the newer revision date.
+- Unique login and credit-card records.
+- A changed secure note that must remain separate for review.
+
+All values are fake and use `.invalid` domains where applicable.

tests/fixtures/sample-export-a.json

@@ -0,0 +1,77 @@
+{
+  "encrypted": false,
+  "folders": [
+    {"id": "folder-work", "name": "Work"},
+    {"id": "folder-personal", "name": "Personal"}
+  ],
+  "collections": [],
+  "items": [
+    {
+      "id": "a-exact",
+      "organizationId": null,
+      "folderId": "folder-work",
+      "type": 1,
+      "reprompt": 0,
+      "name": "Example Portal — Old Label",
+      "notes": "Synthetic exact duplicate; safe fake data.",
+      "favorite": false,
+      "login": {
+        "username": "alice@example.invalid",
+        "password": "Fake-Example-Password-123!",
+        "uris": [{"match": null, "uri": "https://example.com"}],
+        "totp": null
+      },
+      "fields": [],
+      "revisionDate": "2026-01-10T12:00:00.000Z"
+    },
+    {
+      "id": "a-conflict",
+      "organizationId": null,
+      "folderId": "folder-work",
+      "type": 1,
+      "reprompt": 0,
+      "name": "Acme Cloud",
+      "notes": "Older synthetic credential.",
+      "favorite": true,
+      "login": {
+        "username": "demo-user",
+        "password": "Old-Fake-Password!",
+        "uris": [{"match": null, "uri": "https://acme.invalid/login"}],
+        "totp": "JBSWY3DPEHPK3PXP"
+      },
+      "fields": [{"name": "Environment", "value": "test", "type": 0}],
+      "revisionDate": "2026-02-01T12:00:00.000Z"
+    },
+    {
+      "id": "a-unique",
+      "organizationId": null,
+      "folderId": "folder-personal",
+      "type": 1,
+      "reprompt": 0,
+      "name": "A Only Service",
+      "notes": "Only in export A.",
+      "favorite": false,
+      "login": {
+        "username": "a-user",
+        "password": "A-Only-Fake-Secret!",
+        "uris": [{"match": null, "uri": "https://a-only.invalid"}],
+        "totp": null
+      },
+      "fields": [],
+      "revisionDate": "2026-01-15T12:00:00.000Z"
+    },
+    {
+      "id": "a-note",
+      "organizationId": null,
+      "folderId": "folder-personal",
+      "type": 2,
+      "reprompt": 0,
+      "name": "Travel Note",
+      "notes": "Passport reminder — synthetic fixture only.",
+      "favorite": false,
+      "secureNote": {"type": 0},
+      "fields": [],
+      "revisionDate": "2026-01-20T12:00:00.000Z"
+    }
+  ]
+}

tests/fixtures/sample-export-b.json

@@ -0,0 +1,79 @@
+{
+  "encrypted": false,
+  "folders": [
+    {"id": "folder-work-b", "name": "Work"},
+    {"id": "folder-personal-b", "name": "Personal"}
+  ],
+  "collections": [],
+  "items": [
+    {
+      "id": "b-exact",
+      "organizationId": null,
+      "folderId": "folder-work-b",
+      "type": 1,
+      "reprompt": 0,
+      "name": "Example Portal — New Label",
+      "notes": "Synthetic exact duplicate; safe fake data.",
+      "favorite": true,
+      "login": {
+        "username": "ALICE@EXAMPLE.INVALID",
+        "password": "Fake-Example-Password-123!",
+        "uris": [{"match": null, "uri": "https://www.example.com/"}],
+        "totp": null
+      },
+      "fields": [],
+      "revisionDate": "2026-03-10T12:00:00.000Z"
+    },
+    {
+      "id": "b-conflict",
+      "organizationId": null,
+      "folderId": "folder-work-b",
+      "type": 1,
+      "reprompt": 0,
+      "name": "Acme Cloud",
+      "notes": "Newer synthetic credential.",
+      "favorite": true,
+      "login": {
+        "username": "DEMO-USER",
+        "password": "New-Fake-Password!",
+        "uris": [{"match": null, "uri": "https://www.acme.invalid/login/"}],
+        "totp": "KRSXG5A="
+      },
+      "fields": [{"name": "Environment", "value": "production", "type": 0}],
+      "revisionDate": "2026-03-01T12:00:00.000Z"
+    },
+    {
+      "id": "b-unique",
+      "organizationId": null,
+      "folderId": "folder-personal-b",
+      "type": 3,
+      "reprompt": 0,
+      "name": "Synthetic Reward Card",
+      "notes": "Fake card data; never use.",
+      "favorite": false,
+      "card": {
+        "cardholderName": "Test Person",
+        "brand": "Visa",
+        "number": "4111111111111111",
+        "expMonth": "12",
+        "expYear": "2099",
+        "code": "000"
+      },
+      "fields": [],
+      "revisionDate": "2026-02-20T12:00:00.000Z"
+    },
+    {
+      "id": "b-note",
+      "organizationId": null,
+      "folderId": "folder-personal-b",
+      "type": 2,
+      "reprompt": 0,
+      "name": "Travel Note",
+      "notes": "Passport reminder — synthetic fixture updated.",
+      "favorite": false,
+      "secureNote": {"type": 0},
+      "fields": [{"name": "Source", "value": "B", "type": 0}],
+      "revisionDate": "2026-03-05T12:00:00.000Z"
+    }
+  ]
+}