fix: resolve DEBT-017 duplicate ApprovalWorkflow implementation

Adopt Features/ApprovalWorkflow/ (wired into Program.cs, reachable over
HTTP) as the sole VS-26 (formerly VS-03) maker-checker approval slice.
Delete the dead, [DontRegister]'d duplicate under
ApprovalWorkflow/ (Workstream H) and its dedicated test file, which had
been misleadingly credited with "20/20 tests PASS" while being
unreachable at runtime.

- Sql.cs: fix the same Dapper DateOnly-parameter-binding bug that was
  already found and fixed in the now-deleted implementation
  (commit 2ccf74c) but had not been ported to this one; InsertProposalAsync
  would have failed 100% of the time against a real database.
- tests/.../ApprovalWorkflow/ApprovalWorkflowTests.cs: new Handler+Sql+
  real-Postgres integration coverage (create/approve/activate role
  gating, maker!=checker separation of duties, evidence attachment,
  DateOnly round-trip, list filtering) replacing the deleted dead-code
  suite at the same path.
- ApprovalWorkflowPolicyTests.cs: extended (5->10 cases) rather than
  replaced, since it already tested the kept implementation's Policy.
- Program.cs: drop the reference comment to the deleted namespace.
- TECH_DEBT_REGISTER.md: DEBT-017 marked Completed (DB verification
  pending); corrected stale DEBT-023 to point at this resolution;
  registered two residual gaps discovered (not introduced) by this
  cleanup as DEBT-025 (no GET /approvals/{id}, evidence unreachable via
  HTTP) and DEBT-026 (no wired Draft->Proposed transition, so the
  approve/activate path is currently unreachable end-to-end via HTTP).
- WBS_PROGRESS_TRACKER.csv / CURRENT_ROADMAP.md: AEG-VS-26-01 kept
  BLOCKED, not COMPLETED — no PostgreSQL was reachable in this session
  (127.0.0.1:5432 connection refused), so the 8 new integration tests
  are unverified; only the 10 pure-Policy tests were confirmed passing.

Cherry-picked cedc8d7/8c777df from docs/wbs-tracker-current-state onto
this worktree branch first, to bring in the VS-26 renumbering and
ADR-WBS-001 that this task's brief assumed already existed.

dotnet build -c Release: 0 errors/0 warnings.
dotnet test --filter "FullyQualifiedName~ApprovalWorkflow" -c Release:
10 passed (Policy, no DB), 15 failed (DB connection refused - includes
6 unrelated pre-existing tests matched by the filter substring).

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

src/KArtSell.Host/Program.cs

@@ -208,7 +208,7 @@ builder.Services.AddScoped<KArtSell.Modules.ModelOperations.PortfolioReconciliat
 builder.Services.AddScoped<KArtSell.Modules.ModelOperations.PortfolioReconciliation.ReconciliationEngine>();
 builder.Services.AddScoped<KArtSell.Modules.ModelOperations.PortfolioReconciliation.ReconcileTradeHandler>();
 
-// Approval Workflow (VS-03, maker-checker)
+// Approval Workflow (VS-26, formerly VS-03; maker-checker — see docs/DECISIONS/ADR-WBS-001-slice-renumbering.md)
 builder.Services.AddScoped(sp => new KArtSell.Modules.ModelOperations.Features.ApprovalWorkflow.ApprovalWorkflowSql(connectionString));
 builder.Services.AddScoped<KArtSell.Modules.ModelOperations.Features.ApprovalWorkflow.CreateApprovalProposalHandler>();
 builder.Services.AddScoped<KArtSell.Modules.ModelOperations.Features.ApprovalWorkflow.ApproveApprovalHandler>();