test(onboarding-migration): add coverage for dropped ticked milestone keys

Add one test case to cover the scenario where old milestone keys that
don't map to the new template (amc_start, setup_done for SMS) are ticked
and should be counted in the migration's dropped tally. Verifies both
dropped and carried counts are accurate.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/hq/test/migrate-onboarding-templates.test.ts

@@ -121,6 +121,47 @@ describe('onboarding template migration', () => {
     expect((audits[0] as unknown as { n: number }).n).toBe(1)
   })
 
+  it('counts ticked dropped keys (unmapped or not in new template)', async () => {
+    const cmId = await makeSmsClientModule()
+    // Insert old generic rows with two ticked keys that will be dropped:
+    // - amc_start: unmapped (not in KEY_MAP)
+    // - setup_done: maps to 'setup_configuration', but SMS template doesn't have it
+    // Plus one carried key (installed -> installation) to verify carried count too.
+    const rows: [string, number, string | null][] = [
+      ['amc_start', 1, '2026-02-15'],        // ticked, unmapped -> dropped
+      ['setup_done', 1, '2026-03-01'],       // ticked, maps to setup_configuration but SMS template lacks it -> dropped
+      ['installed', 1, '2026-03-25'],        // ticked, maps to installation which IS in SMS template -> carried
+      ['advance_paid', 0, null],
+      ['go_live', 0, null],
+      ['balance_paid', 0, null],
+    ]
+    for (const [i, r] of rows.entries()) {
+      await db.run(
+        `INSERT INTO project_milestone (id,client_module_id,key,label,done,done_on,sort)
+         VALUES (?,?,?,?,?,?,?)`,
+        `m${i}`, cmId, r[0], String(r[0]), r[1], r[2], i,
+      )
+    }
+
+    const res = await migrateOnboardingTemplates(db)
+    expect(res.projects).toBe(1)
+    expect(res.carried).toBe(1) // only installed -> installation
+    expect(res.dropped).toBe(2) // amc_start (unmapped) + setup_done (not in SMS template)
+
+    // Verify the dropped keys are gone from the migrated template
+    const ms = await listProjectMilestones(db, cmId)
+    expect(ms.map((m) => m.key)).toEqual([
+      'document_collection', 'dlt_registration', 'account_creation', 'installation',
+      'testing', 'training', 'go_live', 'advance_payment', 'balance_payment',
+    ])
+    expect(ms.some((m) => m.key === 'amc_start' || m.key === 'setup_done')).toBe(false)
+
+    // Verify the carried installation tick is preserved
+    const installation = ms.find((m) => m.key === 'installation')!
+    expect(installation.done).toBe(true)
+    expect(installation.doneOn).toBe('2026-03-25')
+  })
+
   it('leaves a module without a per-module template untouched', async () => {
     const client = await createClient(db, 'u1', { name: 'Other Society', stateCode: '32' })
     const mod = await createModule(db, 'u1', { code: 'NOTEMPLATE', name: 'No Template Module' })