android: byte-level upload progress + debug logging; document 28.3

- UploadWorker: ProgressRequestBody (okio ForwardingSink) tracks real bytes
  sent including already-received chunks, instead of chunk count
- Robust chunk reads (loop skip/read) + Log.d/Log.e debug logging
- DashcamViewModel: upload state/progress debug logging
- android/plan.md + PLAN.md: 28.3 marked in progress with built items

android/plan.md

@@ -124,33 +124,34 @@ android/
 - Phase 28.2 — dashcam video browser + WiFi download
 - fix: downloads use WorkManager foreground service + inline progress
 
-### 28.3 — Cellular upload ⬜ NOT STARTED
+### 28.3 — Cellular upload 🚧 IN PROGRESS (2026-08-12)
 **Depends on: 28.2 (files on phone local storage).**
 
-#### 28.3.1 — Server upload data layer
-- [ ] Retrofit interface for server chunked upload:
+#### 28.3.1 — Server upload data layer ✅ DONE
+- [x] Retrofit interface for server chunked upload (`data/remote/ServerApi.kt`):
   - `GET /api/v1/dashcam/upload/status?sha256={hash}` → `UploadStatus`
   - `POST /api/v1/dashcam/upload/chunk` → multipart (file chunk, sha256, chunk_index, total_chunks)
-- [ ] Data classes: `UploadStatus` (already_uploaded, received_chunk_indices, total_chunks)
-- [ ] Commit: `feat: server chunked upload API`
+- [x] Data classes: `UploadStatus` (already_uploaded, received_chunk_indices, total_chunks)
 
-#### 28.3.2 — Upload worker
-- [ ] WorkManager `CoroutineWorker`:
-  - Input: file local URI, sha256, relative_path
-  - Step 1: check `/status` for already-received chunks
+#### 28.3.2 — Upload worker ✅ DONE
+- [x] WorkManager `CoroutineWorker` (`UploadWorker.kt`):
+  - Input: filename, server URL, device name, API key
+  - Step 1: compute SHA256, check `/status` for already-received chunks
   - Step 2: read file in 40MB chunks (matching `DASHCAM_CHUNK_SIZE`)
-  - Step 3: POST each missing chunk via cellular-bound OkHttp client
+  - Step 3: POST each missing chunk (skips already-received chunks)
   - Step 4: verify server reports `already_uploaded` after last chunk
-  - Step 5: delete local file copy on success (optional, configurable)
-- [ ] Foreground service notification: "Uploading VID_00234.MOV — 3/8 chunks (37%)"
-- [ ] Retry on failure: WorkManager backoff policy (exponential, max 3 attempts)
-- [ ] Commit: `feat: WorkManager cellular upload worker`
+- [x] Foreground service notification with live % ("Uploading VID_00234.MOV — 62%")
+- [x] Byte-level upload progress via `ProgressRequestBody` (okio `ForwardingSink`) — progress
+  reflects actual bytes sent including already-received chunks, not just chunk count
+- [x] Robust chunk reads (loop `skip()`/`read()` instead of single calls)
+- [x] Debug logging (`Log.d`/`Log.e`, tag `UploadWorker`) throughout
+- [x] Re-upload guard: skips files already on server (`already_uploaded`)
 
-#### 28.3.3 — Upload queue UI
-- [ ] Screen: list of downloaded files waiting to upload
-- [ ] Per-file: status (queued / uploading / done / failed), progress bar, retry button
+#### 28.3.3 — Upload queue UI 🚧 IN PROGRESS
+- [x] Downloads screen shows per-file upload status + inline progress bar
+- [x] In-app test file generator for upload testing
 - [ ] "Upload all" button → enqueue all pending files
-- [ ] Observation: watch WorkManager `WorkInfo` via `LiveData`/`Flow` for real-time status
+- [ ] Retry button per failed file
 - [ ] Commit: `feat: upload queue screen`
 
 ### 28.4 — Live dashboard ⬜ NOT STARTED