refactor: Improve person creation and identification logic with optional fields handling

This commit refactors the person creation and identification logic to handle optional fields more effectively. The `date_of_birth` field in the `PersonCreateRequest` schema is now optional, and the frontend has been updated to trim whitespace from name fields before submission. Additionally, the identification logic has been enhanced to ensure that only non-empty names are considered valid. Documentation has been updated to reflect these changes.

frontend/src/api/people.ts

@@ -28,7 +28,7 @@ export interface PersonCreateRequest {
   last_name: string
   middle_name?: string
   maiden_name?: string
-  date_of_birth: string
+  date_of_birth?: string | null
 }
 
 export interface PersonUpdateRequest {

frontend/src/pages/Identify.tsx

@@ -82,8 +82,10 @@ export default function Identify() {
   const restorationCompleteRef = useRef(false)
 
   const canIdentify = useMemo(() => {
-    return Boolean((personId && currentFace) || (firstName && lastName && dob && currentFace))
-  }, [personId, firstName, lastName, dob, currentFace])
+    if (!currentFace) return false
+    if (personId) return true
+    return Boolean(firstName.trim() && lastName.trim())
+  }, [personId, firstName, lastName, currentFace])
 
   const loadFaces = async (clearState: boolean = false, ignorePhotoIds: boolean = false) => {
     setLoadingFaces(true)
@@ -589,6 +591,11 @@ export default function Identify() {
   const handleIdentify = async () => {
     if (!currentFace) return
     setBusy(true)
+    const trimmedFirstName = firstName.trim()
+    const trimmedLastName = lastName.trim()
+    const trimmedMiddleName = middleName.trim()
+    const trimmedMaidenName = maidenName.trim()
+    const trimmedDob = dob.trim()
     const additional = Object.entries(selectedSimilar)
       .filter(([, v]) => v)
       .map(([k]) => Number(k))
@@ -597,11 +604,17 @@ export default function Identify() {
       if (personId) {
         payload.person_id = personId
       } else {
-        payload.first_name = firstName
-        payload.last_name = lastName
-        payload.middle_name = middleName || undefined
-        payload.maiden_name = maidenName || undefined
-        payload.date_of_birth = dob
+        payload.first_name = trimmedFirstName
+        payload.last_name = trimmedLastName
+        if (trimmedMiddleName) {
+          payload.middle_name = trimmedMiddleName
+        }
+        if (trimmedMaidenName) {
+          payload.maiden_name = trimmedMaidenName
+        }
+        if (trimmedDob) {
+          payload.date_of_birth = trimmedDob
+        }
       }
       await facesApi.identify(currentFace.id, payload)
       // Optimistic: remove identified faces from list
@@ -948,7 +961,7 @@ export default function Identify() {
                       disabled={!!personId} />
                   </div>
                   <div className="col-span-2">
-                    <label className="block text-sm font-medium text-gray-700">Date of Birth *</label>
+                    <label className="block text-sm font-medium text-gray-700">Date of Birth (optional)</label>
                     <input type="date" value={dob} onChange={(e) => {
                       setDob(e.target.value)
                       setPersonId(undefined) // Clear person selection when typing