fix(api): close M5 frontend contract gaps

docs/BACKEND/API_GUIDES/V2/mobile-coding-agent-spec.md

@@ -23,6 +23,7 @@ Supporting docs:
 - Send `Idempotency-Key` on every write route.
 - Treat `order`, `shift`, `shiftRole`, and `assignment` as different objects.
 - For staff shift applications, `roleId` must come from the response of `GET /staff/shifts/open`.
+- Treat API timestamp fields as UTC and convert them to local time in the app.
 
 ## 2) What is implemented now
 
@@ -145,6 +146,8 @@ Rules:
 - worker rating happens through `POST /client/coverage/reviews`
 - the same endpoint also supports `markAsFavorite` to add or remove a worker from business favorites
 - blocking a worker is done through the same endpoint using `markAsBlocked`
+- coverage shift items now include `locationName` and `locationAddress`
+- assigned worker items now include `hasReview`
 - dispatch ranking order is:
   1. `CORE`
   2. `CERTIFIED_LOCATION`
@@ -216,6 +219,7 @@ Important:
 
 - `GET /staff/session`
 - `GET /staff/dashboard`
+- `GET /staff/profile/stats`
 - `GET /staff/profile-completion`
 
 ### Availability
@@ -250,6 +254,7 @@ Staff shift detail and list rules:
 - assigned shifts include `clientName`, `hourlyRate`, `totalRate`, `startTime`, `endTime`
 - shift detail includes `clientName`, `latitude`, `longitude`, `hourlyRate`, `totalRate`
 - completed shifts include `date`, `clientName`, `startTime`, `endTime`, `hourlyRate`, `totalRate`
+- `GET /staff/profile/stats` returns `totalShifts`, `averageRating`, `ratingCount`, `onTimeRate`, `noShowCount`, `cancellationCount`, `reliabilityScore`
 
 ### Clock in / clock out
 
@@ -266,6 +271,7 @@ Clock-in payload rules:
 - send `overrideReason` only when geo override is allowed
 - send `proofNonce` and `proofTimestamp` on attendance writes
 - send `attestationProvider` and `attestationToken` only if the device has them
+- if backend returns `ALREADY_CLOCKED_IN`, treat it as a valid retry-state signal and refresh attendance/session state
 
 Clock-in read rules: