feat(hometitle): add Backend Router — HomeTitle (Property Monitoring)

- Add hometitle schema (Valibot input schemas)
- Add change detector (fuzzy matching, severity, change detection)
- Add scanner module (geocoding, county records placeholder)
- Add hometitle service (property CRUD, scan, alert pipeline)
- Add hometitle router (7 tRPC procedures)
- Wire into api root
- Add alert type 'property_change' to enum
- Write unit tests (10 tests, all passing)

web/src/server/api/schemas/hometitle.ts

@@ -0,0 +1,23 @@
+import { object, string, minLength, optional, number, picklist } from "valibot";
+
+export const AddPropertySchema = object({
+  address: string([minLength(1)]),
+  parcelId: optional(string()),
+  ownerName: optional(string()),
+});
+
+export const RemovePropertySchema = object({
+  propertyId: string([minLength(1)]),
+});
+
+export const GetSnapshotsSchema = object({
+  propertyId: string([minLength(1)]),
+});
+
+export const GetChangesSchema = object({
+  propertyId: string([minLength(1)]),
+  severity: optional(picklist(["info", "warning", "critical"])),
+  changeType: optional(picklist(["tax_change", "deed_change", "ownership_transfer", "lien_filing", "metadata_change"])),
+});
+
+export const RunScanSchema = object({});