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.Modules.ModelOperations/Features/ApprovalWorkflow/README.md

@@ -1,9 +1,27 @@
-# VS-03: Model Approval Workflow (Maker-Checker Governance)
+# VS-26 (formerly VS-03): Model Approval Workflow (Maker-Checker Governance)
 
 ## Overview
 
 This slice implements a maker-checker approval workflow for model activation with separation of duties and immutable audit trail.
 
+**This is now the sole implementation of this slice.** A second, functionally-overlapping copy
+(`src/KArtSell.Modules.ModelOperations/ApprovalWorkflow/`, no `Features/` prefix) existed
+alongside this one from 2026-08-07 to 2026-08-08; it was dead code (all 4 endpoints
+`[DontRegister]`'d to avoid a duplicate-route crash at Host startup) despite having 20/20
+passing tests, while *this* implementation — the one actually wired into `Program.cs` and
+reachable over HTTP — had no dedicated tests. See `TECH_DEBT_REGISTER.md` DEBT-017 and
+`docs/DECISIONS/ADR-WBS-001-slice-renumbering.md` for the full history. The old implementation
+and its test file were deleted on 2026-08-08 once this one gained equivalent integration-test
+coverage (`tests/KArtSell.Integration.Tests/ApprovalWorkflow/ApprovalWorkflowTests.cs`).
+
+**Bug fixed 2026-08-08 (as part of DEBT-017):** `InsertProposalAsync` in `Sql.cs` passed
+`EffectiveAt` (a `DateOnly`) directly as a Dapper parameter. The now-deleted implementation hit
+the identical failure against a real database (commit `2ccf74c`) — Npgsql/Dapper in this
+environment cannot bind a bare `DateOnly` value; it needs an explicit `::date` cast plus a
+`"yyyy-MM-dd"` string parameter. That fix has been ported here. **This has not been re-verified
+against a live PostgreSQL instance in this session** (none was reachable) — see "Test status"
+below.
+
 ## Architecture
 
 ### State Machine
@@ -52,6 +70,16 @@ PROPOSED (maker submits)
    - POST /approvals (create proposal)
    - GET /approvals (list proposals)
    - POST /approvals/{id}/approve (approve proposal)
+   - ⚠️ **No `GET /approvals/{id}`.** The deleted duplicate implementation had a single-proposal
+     fetch endpoint that included the evidence list in its response; this implementation has no
+     equivalent, so evidence attached during approval is currently unreachable via HTTP (it can
+     only be read back through `ApprovalWorkflowSql` directly, e.g. in tests). Not fixed here —
+     out of scope for DEBT-017 (duplicate-implementation cleanup); tracked as **DEBT-025**.
+   - ⚠️ **No wired "submit for review" transition.** `ApprovalWorkflowPolicy.CanProposeForReview`
+     exists but no `Handler` or `Endpoint` calls it, so nothing in the running application ever
+     moves a proposal from `Draft` to `Proposed`. `ActivateModelHandler` and `ApproveApprovalHandler`
+     both require `Proposed`/`Approved` respectively, so as shipped a created proposal cannot
+     reach `Approved` through the HTTP API alone. Also not fixed here — tracked as **DEBT-026**.
 
 ## API Contracts
 
@@ -178,15 +206,25 @@ CREATE TABLE model_operations.approval_events (
 
 ## Tests
 
-Unit tests cover:
-- RBAC enforcement (Maker, Checker, SRE roles)
-- Separation of duties (Checker ≠ Maker)
-- State machine transitions
-- RBAC violations
+- `tests/KArtSell.Integration.Tests/ApprovalWorkflowPolicyTests.cs` — pure `ApprovalWorkflowPolicy`
+  unit tests (no DB): RBAC enforcement (Maker/Checker/SRE), separation of duties, valid/invalid
+  state transitions. Fast, deterministic.
+- `tests/KArtSell.Integration.Tests/ApprovalWorkflow/ApprovalWorkflowTests.cs` — Handler + Sql +
+  real PostgreSQL integration tests: create (role-gated), approve (maker≠checker, evidence
+  attachment), activate (SRE-gated), `EffectiveAt` `DateOnly` round-trip through a real `date`
+  column, list filtering.
+
+**Test status as of 2026-08-08 (DEBT-017 resolution session): written but not run against a live
+database.** No PostgreSQL was reachable at `127.0.0.1:5432` in that session (no SSH tunnel to
+178.104.200.7 open). `dotnet build -c Release` was confirmed green; `dotnet test --filter
+"FullyQualifiedName~ApprovalWorkflow"` was run and its actual outcome (pass, fail, or DB
+connection error) is recorded in `TECH_DEBT_REGISTER.md` DEBT-017 and
+`docs/CURRENT/CATALOGS/WBS_PROGRESS_TRACKER.csv` row `AEG-VS-26-01` — check those before treating
+this slice as verified.
 
 Run tests:
 ```bash
-dotnet test --filter "ApprovalWorkflowPolicyTests"
+dotnet test --filter "FullyQualifiedName~ApprovalWorkflow" -c Release
 ```
 
 ## AGENTS.md v16.0 Compliance
@@ -194,25 +232,37 @@ dotnet test --filter "ApprovalWorkflowPolicyTests"
 - ✅ **SOLID:** Separate Endpoint/Handler/Policy/Sql per operation
 - ✅ **Complexity:** Each handler ≤200 lines
 - ✅ **Audit:** All state changes logged with correlation_id
-- ✅ **Necessity:** Grounded in VS-03 SLICE_SPEC
-- ✅ **Normalization:** 3NF schema, append-only events
+- ✅ **Necessity:** Grounded in VS-26 (formerly VS-03) SLICE_SPEC
+- ⚠️ **Normalization:** Writes mutate `approval_proposals` in place (`UPDATE ... revision =
+  revision + 1`) rather than appending a new revision row, because `id` is the sole `PRIMARY KEY`
+  in migration `0036_approval_workflow.sql` (no `(id, published_at)` composite key) — an
+  append-only INSERT would violate that constraint on the second write. This is a real deviation
+  from CLAUDE.md's "new state appended as new revision" rule; it is pre-existing (present before
+  this session) and schema-level, so fixing it is out of scope for DEBT-017. `GetProposalAsync`
+  correspondingly has no `published_at <= cutoff` PIT filter, since there is only ever one row.
 - ✅ **Simplicity:** State machine clearly visible
 - ✅ **Pattern:** Vertical Slice standard
 - ✅ **Guardrails:** RBAC enforced, no privilege escalation
 - ✅ **Traceability:** Correlation_id + evidence linking
-- ✅ **Safety:** Idempotent, rollback-safe
+- ⚠️ **Safety:** DateOnly parameter binding bug fixed 2026-08-08; unverified against a live DB
+  this session (see "Test status" above)
 - ✅ **Maturity:** Spec complete before code
-- ✅ **Right-Way:** No shortcuts, formal approval workflow
-- ✅ **Debt:** No new tech debt
+- ✅ **Right-Way:** Duplicate implementation resolved per DEBT-017, not worked around
+- ⚠️ **Debt:** DEBT-017 (duplicate implementation) resolved; two residual gaps discovered by this
+  cleanup (predate it, not introduced by it) are registered as DEBT-025 (no `GET /approvals/{id}`)
+  and DEBT-026 (no wired Draft→Proposed transition)
 
 ## Related Specifications
 
 - **VS-00:** PIT envelope (published_at, correlation_id, revision)
 - **VS-02:** Governance foundation (data sources, policies)
-- **VS-04:** Audit trail (events logged by this slice)
+- **VS-27 (formerly VS-04):** Audit trail (events logged by this slice)
 - **Compliance:** Maker-checker separation, evidence linkage
 
 ---
 
-**Status:** ✅ IMPLEMENTATION COMPLETE  
-**Co-Authored-By:** Claude Haiku 4.5 <noreply@anthropic.com>
+**Status:** Backend implementation is the canonical (sole) copy of this slice as of 2026-08-08;
+integration tests exist but are unverified against a live database (see "Test status"). Not
+"IMPLEMENTATION COMPLETE" until that verification runs and the two residual gaps above are
+resolved or explicitly accepted.
+**Co-Authored-By:** Claude Sonnet 5 <noreply@anthropic.com>

src/KArtSell.Modules.ModelOperations/Features/ApprovalWorkflow/Sql.cs

@@ -55,7 +55,7 @@ public class ApprovalWorkflowSql
             INSERT INTO model_operations.approval_proposals
             (id, model_id, status, created_by, created_at, justification, effective_at,
              published_at, revision, correlation_id)
-            VALUES (@id, @modelId, @status, @createdBy, @createdAt, @justification, @effectiveAt,
+            VALUES (@id, @modelId, @status, @createdBy, @createdAt, @justification, @effectiveAt::date,
                     @publishedAt, @revision, @correlationId)
             RETURNING id
             """;
@@ -69,7 +69,11 @@ public class ApprovalWorkflowSql
             proposal.CreatedBy,
             proposal.CreatedAt,
             proposal.Justification,
-            proposal.EffectiveAt,
+            // Dapper cannot bind DateOnly directly as an Npgsql parameter value (see TECH_DEBT_REGISTER.md
+            // DEBT-017); the identical failure was found and fixed the same way in the now-deleted
+            // ApprovalSql.cs (commit 2ccf74c) after it crashed 100% of proposal-creation calls against a
+            // real database.
+            effectiveAt = proposal.EffectiveAt.ToString("yyyy-MM-dd"),
             proposal.PublishedAt,
             proposal.Revision,
             proposal.CorrelationId