refactor: move buildable .NET source into src/, update CI/doc paths

Groups the repo root into src (buildable source), docs (already existed),
and everything else (db/, scripts/, tests/, deploy/ - deployment/ops/test
assets that aren't compiled, already organized as their own folders). CI
now only needs src/ to build: dotnet restore/build/test/publish all point
at src/TaxBaik.sln, src/TaxBaik.Web/, src/TaxBaik.Proxy/.

- git mv every project (Domain, Infrastructure, Application,
  Application.Tests, Web, Web.Client, Proxy) and TaxBaik.sln into src/ as a
  unit, so relative ProjectReference/.sln paths stay valid unchanged.
- .gitea/workflows/deploy.yml: 6 dotnet restore/clean/build/test/publish
  invocations now point at src/. db/migrations and scripts/ stay at root
  (deploy_gb.sh and browser-e2e.yml only touch published output and the
  deployed URL, not source paths - verified, no changes needed there).
- scripts/validate_admin_render.sh: admin render-mode file paths now
  src/TaxBaik.Web.Client/...
- scripts/validate_kst_timestamps.sh: dropped deploy.sh from its target
  list - that script was removed in the prior cleanup commit (dead, no
  CI workflow referenced it) but this validator still expected it to exist.
- CLAUDE.md, docs/ENGINEERING_HARNESS.md, docs/ADMIN_PATTERN_CRITIQUE_WBS.md:
  updated project-structure diagram, dotnet run/build commands, and grep
  targets to the new src/ paths (also fixed a pre-existing stale path in
  ADMIN_PATTERN_CRITIQUE_WBS.md that still said TaxBaik.Web/Components/Admin
  from before that ever moved to TaxBaik.Web.Client).
- Added a Repo Root harness rule + Architecture Guardrail entries: new files
  belong under src/docs/tests/scripts/db/deploy, not loose at root; temp
  work stays outside the repo (or under a gitignored .scratch/) and is
  never committed.

Verified locally: dotnet build/test src/TaxBaik.sln (26/26 tests), and all
three scripts/validate_*.sh pass against the new layout.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

TaxBaik.Application/Services/RevenueTrackingService.cs

@@ -1,55 +0,0 @@
-namespace TaxBaik.Application.Services;
-
-using TaxBaik.Domain.Entities;
-using TaxBaik.Domain.Interfaces;
-
-public class RevenueTrackingService(IRevenueTrackingRepository repository)
-{
-    public async Task<int> CreateAsync(int clientId, string invoiceNumber, DateTime invoiceDate,
-        decimal amount, string? serviceType = null, DateTime? dueDate = null, CancellationToken ct = default)
-    {
-        if (clientId <= 0)
-            throw new ValidationException("유효한 고객을 선택하세요.");
-        if (string.IsNullOrWhiteSpace(invoiceNumber))
-            throw new ValidationException("인보이스 번호를 입력하세요.");
-        if (amount <= 0)
-            throw new ValidationException("금액은 0보다 커야 합니다.");
-
-        var revenue = new RevenueTracking
-        {
-            ClientId = clientId,
-            InvoiceNumber = invoiceNumber.Trim(),
-            InvoiceDate = invoiceDate,
-            Amount = amount,
-            ServiceType = string.IsNullOrWhiteSpace(serviceType) ? null : serviceType.Trim(),
-            DueDate = dueDate,
-            PaymentStatus = "pending",
-            CreatedAt = DateTime.UtcNow,
-            UpdatedAt = DateTime.UtcNow
-        };
-
-        return await repository.CreateAsync(revenue, ct);
-    }
-
-    public async Task<IEnumerable<RevenueTracking>> GetByClientIdAsync(int clientId, CancellationToken ct = default) =>
-        await repository.GetByClientIdAsync(clientId, ct);
-
-    public async Task<IEnumerable<RevenueTracking>> GetAllAsync(CancellationToken ct = default) =>
-        await repository.GetAllAsync(ct);
-
-    public async Task<IEnumerable<RevenueTracking>> GetPendingPaymentsAsync(CancellationToken ct = default) =>
-        await repository.GetPendingPaymentsAsync(ct);
-
-    public async Task<IEnumerable<RevenueTracking>> GetMonthlyRevenueAsync(DateTime month, CancellationToken ct = default)
-    {
-        var startDate = new DateTime(month.Year, month.Month, 1);
-        var endDate = startDate.AddMonths(1).AddDays(-1);
-        return await repository.GetByDateRangeAsync(startDate, endDate, ct);
-    }
-
-    public async Task MarkPaidAsync(int id, DateTime paymentDate, CancellationToken ct = default) =>
-        await repository.MarkPaidAsync(id, paymentDate, ct);
-
-    public async Task<decimal> GetTotalRevenueAsync(DateTime startDate, DateTime endDate, CancellationToken ct = default) =>
-        await repository.GetTotalRevenueAsync(startDate, endDate, ct);
-}