# Fix Peers API 500 + Add Delete Device to Devices List

## TL;DR
> **Quick Summary**: Fix `HWID` unique constraint violation causing 500 on POST `/api/v1/peers` by making `HWID` nullable; add delete button to Devices.vue list view
> 
> **Deliverables**:
> - Backend: HWID model change `string` → `*string`, fix CreatePeer/CreateDevice
> - Frontend: Delete button in Devices.vue table rows
> - Migration: SQL to convert existing empty HWIDs to NULL + container restart
> 
> **Estimated Effort**: Short
> **Parallel Execution**: YES

## Context
### Root Cause
- `Device.HWID` is `string` with `uniqueIndex`. `CreatePeer` sets `HWID: ""` which collides with other devices having empty HWID → SQLSTATE 23505
- Fix: make HWID `*string` (nullable), PostgreSQL treats NULLs as distinct in unique constraints

### Delete Missing
- Backend: `DELETE /devices/:id` exists at `main.go:176`, `devicesHandler.Delete` in `devices.go:235`
- API: `deleteDevice(id)` exists in `devices.ts:50`
- DeviceDetail: has delete button with confirm dialog
- Devices.vue: Actions column only has View, Config, Firewall — no Delete

## TODOs

- [ ] 1. Backend: Change HWID to `*string` in Device model

  **What to do**:
  - Edit `apps/server-core/internal/models/models.go` line 60:
    - Change `HWID string \`gorm:"column:hwid;uniqueIndex;size:64"\``
    - To `HWID *string \`gorm:"column:hwid;uniqueIndex;size:64"\``

  **Must NOT do**:
  - Don't change any other fields in the model

  **Recommended Agent Profile**: `unspecified-high` (precise Go struct edit)

  **QA Scenarios**:
  ```
  Scenario: Verify build after model change
    Tool: Bash
    Steps:
      1. cd apps/server-core && go build ./...
    Expected Result: No compilation errors
    Evidence: .sisyphus/evidence/task-1-build.txt
  ```

- [ ] 2. Backend: Fix CreatePeer to not set empty HWID

  **What to do**:
  - Edit `apps/server-core/api/peers.go` — remove `HWID: ""` line (line 96)
  - Since `HWID` is now `*string`, the zero value (nil) is correct — it won't violate unique constraint
  - Keep `RegTokenHash: ""` as-is (no unique index on that)

  **QA Scenarios**:
  ```
  Scenario: Build passes after fix
    Tool: Bash
    Steps:
      1. cd apps/server-core && go build ./...
    Expected Result: Clean build
    Evidence: .sisyphus/evidence/task-2-build.txt
  ```

- [ ] 3. Backend: Fix CreateDevice to not set empty HWID

  **What to do**:
  - Edit `apps/server-core/api/devices.go` — verify `Create` function (line 84-89) doesn't set HWID
  - It currently doesn't set HWID at all, so with `*string` it will default to nil — correct
  - Verify `Delete` function (line 235-255) already works — it does, no changes needed

- [ ] 4. Migration: Convert existing empty HWIDs to NULL on server

  **What to do**:
  - SSH into 172.20.8.191 and run SQL against the postgres container:
  ```bash
  docker exec nexus-guard-suite-postgres-1 psql -U nexusguard -d nexusguard -c "UPDATE devices SET hwid = NULL WHERE hwid = '';"
  ```
  - Then restart server-core container:
  ```bash
  docker restart nexus-guard-suite-server-core-1
  ```

  **QA Scenarios**:
  ```
  Scenario: Verify empty HWIDs are now NULL
    Tool: Bash
    Steps:
      1. docker exec nexus-guard-suite-postgres-1 psql -U nexusguard -d nexusguard -c "SELECT count(*) FROM devices WHERE hwid = '';"
    Expected Result: count = 0
    Evidence: .sisyphus/evidence/task-4-sql.txt

  Scenario: Verify POST /api/v1/peers succeeds
    Tool: Bash
    Steps:
      1. Obtain auth token via POST /api/v1/auth/login with admin credentials
      2. POST /api/v1/peers with valid body (name, wg_server_id)
    Expected Result: 201 Created (not 500)
    Evidence: .sisyphus/evidence/task-4-peers-api.txt
  ```

- [ ] 5. Frontend: Add delete button to Devices.vue list

  **What to do**:
  - Edit `apps/dashboard-ui/src/views/Devices.vue`
  - Add delete button in the Actions column (line 34-39), after Firewall button:
    ```html
    <button @click="handleDelete(device.ID, device.Name)" class="text-red-400 hover:text-red-300 font-bold">Delete</button>
    ```
  - Import `deleteDevice` from `../api/devices`
  - Add `handleDelete` function:
    ```typescript
    const handleDelete = async (id: string, name: string) => {
      if (!confirm(`Delete device "${name}"? This will destroy its tunnel and all firewall rules.`)) return
      try {
        await deleteDevice(id)
        store.loadDevices()
      } catch (err: any) {
        alert(err.response?.data?.error || 'Failed to delete device')
      }
    }
    ```

  **Must NOT do**:
  - Don't remove the existing Config/Firewall buttons

  **Recommended Agent Profile**: `visual-engineering` (Vue UI)

  **QA Scenarios**:
  ```
  Scenario: Build passes
    Tool: Bash
    Steps:
      1. cd apps/dashboard-ui && npx vue-tsc --noEmit
    Expected Result: No type errors
    Evidence: .sisyphus/evidence/task-5-tsc.txt
  ```

- [ ] 6. Commit and push changes

  **What to do**:
  - Commit server-core changes
  - Commit dashboard-ui changes  
  - Push both submodules
  - Commit/push root submodule pointer


## Success Criteria
- [ ] `go build ./...` passes
- [ ] `vue-tsc --noEmit` passes
- [ ] POST `/api/v1/peers` returns 201, not 500
- [ ] Devices.vue has a delete button per row that works
- [ ] Existing empty HWIDs migrated to NULL