Initial commit: Purrse personal finance app

Self-hosted, plugin-extensible personal finance manager built with
ASP.NET Core 9.0, Vue 3 + Vuetify 3, and PostgreSQL 17.

Backend (8 .NET projects):
- Core: 19 domain models, 6 enums, 14 DTOs, 12 service interfaces
- Data: EF Core DbContext, 16 entity configurations, category seeder
- API: 14 controllers, 15 services, JWT auth, SignalR, middleware
- Plugins: Abstractions + OFX/CSV/QIF file parsers
- Tests: 28 xUnit tests (fingerprinting, duplicate detection, parsers)

Frontend (Vue 3 + Vuetify 3 + TypeScript):
- 13 views, Pinia stores, Axios API services with JWT interceptors
- Dashboard, accounts, transactions, categories, imports, and more

Deployment:
- Docker Compose (PostgreSQL 17 + .NET API + nginx frontend)
- Auto-migration on startup

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/Purrse.Tests/Helpers/StringSimilarityTests.cs

@@ -0,0 +1,50 @@
+using FluentAssertions;
+using Purrse.Core.Helpers;
+
+namespace Purrse.Tests.Helpers;
+
+public class StringSimilarityTests
+{
+    [Theory]
+    [InlineData("WALMART", "WALMART", 1.0)]
+    [InlineData("WAL-MART STORE #1234", "WALMART", 0.7)]
+    [InlineData("AMAZON.COM", "AMAZON MARKETPLACE", 0.6)]
+    public void Calculate_KnownPairs_ReturnsExpectedRange(string s1, string s2, double minExpected)
+    {
+        var result = StringSimilarityHelper.Calculate(s1, s2);
+        result.Should().BeGreaterOrEqualTo(minExpected);
+    }
+
+    [Fact]
+    public void Calculate_ExactMatch_ReturnsOne()
+    {
+        StringSimilarityHelper.Calculate("Test Payee", "Test Payee").Should().Be(1.0);
+    }
+
+    [Fact]
+    public void Calculate_CaseInsensitive()
+    {
+        var result = StringSimilarityHelper.Calculate("walmart", "WALMART");
+        result.Should().Be(1.0);
+    }
+
+    [Fact]
+    public void Calculate_EmptyString_ReturnsZero()
+    {
+        StringSimilarityHelper.Calculate("", "test").Should().Be(0);
+        StringSimilarityHelper.Calculate("test", "").Should().Be(0);
+    }
+
+    [Fact]
+    public void Calculate_NullString_ReturnsZero()
+    {
+        StringSimilarityHelper.Calculate(null!, "test").Should().Be(0);
+    }
+
+    [Fact]
+    public void Calculate_CompletelyDifferent_ReturnsLowScore()
+    {
+        var result = StringSimilarityHelper.Calculate("ABCDEF", "ZYXWVU");
+        result.Should().BeLessThan(0.5);
+    }
+}

src/Purrse.Tests/Helpers/TransactionFingerprintTests.cs

@@ -0,0 +1,56 @@
+using FluentAssertions;
+using Purrse.Core.Helpers;
+
+namespace Purrse.Tests.Helpers;
+
+public class TransactionFingerprintTests
+{
+    [Fact]
+    public void Generate_SameInputs_ReturnsSameHash()
+    {
+        var accountId = Guid.NewGuid();
+        var date = new DateTime(2024, 1, 15);
+        var amount = -42.50m;
+        var fitId = "FIT123";
+
+        var hash1 = TransactionFingerprint.Generate(accountId, date, amount, fitId);
+        var hash2 = TransactionFingerprint.Generate(accountId, date, amount, fitId);
+
+        hash1.Should().Be(hash2);
+    }
+
+    [Fact]
+    public void Generate_DifferentAmounts_ReturnsDifferentHash()
+    {
+        var accountId = Guid.NewGuid();
+        var date = new DateTime(2024, 1, 15);
+
+        var hash1 = TransactionFingerprint.Generate(accountId, date, -42.50m, "FIT123");
+        var hash2 = TransactionFingerprint.Generate(accountId, date, -42.51m, "FIT123");
+
+        hash1.Should().NotBe(hash2);
+    }
+
+    [Fact]
+    public void Generate_NullFitId_StillWorks()
+    {
+        var accountId = Guid.NewGuid();
+        var date = new DateTime(2024, 1, 15);
+
+        var hash = TransactionFingerprint.Generate(accountId, date, -42.50m, null);
+
+        hash.Should().NotBeNullOrEmpty();
+        hash.Should().HaveLength(64); // SHA256 hex = 64 chars
+    }
+
+    [Fact]
+    public void Generate_DifferentAccounts_ReturnsDifferentHash()
+    {
+        var date = new DateTime(2024, 1, 15);
+
+        var hash1 = TransactionFingerprint.Generate(Guid.NewGuid(), date, -42.50m, null);
+        var hash2 = TransactionFingerprint.Generate(Guid.NewGuid(), date, -42.50m, null);
+
+        hash1.Should().NotBe(hash2);
+    }
+}