test: 492 tests, 78% line coverage

- Device domain: updateFromValues, organizeParameters, identifier
- BaseModel: full CRUD mock tests
- DeviceModel: all methods mocked
- Other models: collectionName verification
- MainStateMachine: start, handleResponse, state transitions
- ConfigurationEvaluationState: init, GPN flow, GPN-unsupported skip
- MongodbProvider: getMongoDb guard
- device_utils: hash determinism
- vitest.config.ts: coverage scope (excludes HTTP layer)
- 492 tests passing, 78% line coverage

tests/unit/utils/device_utils.spec.ts

@@ -0,0 +1,28 @@
+import { describe, it, expect } from 'vitest'
+import { getDeviceHashIdentifier } from '../../../app/utils/device_utils.js'
+
+describe('getDeviceHashIdentifier', () => {
+  it('returns a 24-char hex string', () => {
+    const hash = getDeviceHashIdentifier({ oui: 'F8B7FF', productClass: 'Livebox', serialNumber: 'SN001' })
+    expect(hash).toHaveLength(24)
+    expect(hash).toMatch(/^[0-9a-f]{24}$/)
+  })
+
+  it('is deterministic', () => {
+    const a = getDeviceHashIdentifier({ oui: 'A', productClass: 'B', serialNumber: 'C' })
+    const b = getDeviceHashIdentifier({ oui: 'A', productClass: 'B', serialNumber: 'C' })
+    expect(a).toBe(b)
+  })
+
+  it('different inputs produce different hashes', () => {
+    const a = getDeviceHashIdentifier({ oui: 'A', productClass: 'B', serialNumber: 'C' })
+    const b = getDeviceHashIdentifier({ oui: 'A', productClass: 'B', serialNumber: 'D' })
+    expect(a).not.toBe(b)
+  })
+
+  it('includes manufacturer when provided', () => {
+    const withMfr = getDeviceHashIdentifier({ manufacturer: 'Sagemcom', oui: 'A', productClass: 'B', serialNumber: 'C' })
+    const withoutMfr = getDeviceHashIdentifier({ oui: 'A', productClass: 'B', serialNumber: 'C' })
+    expect(withMfr).not.toBe(withoutMfr)
+  })
+})