Tick off Phase 5 collection/file decryption TODO

README.md

@@ -629,12 +629,16 @@ Phase 4: HTTP client + endpoints
 
 Phase 5: collections and files
 
-- [ ] `listCollections()` paginating on `sinceTime` until empty
-- [ ] Decrypt per-collection key with master key
-- [ ] Decrypt collection name with collection key
-- [ ] `listFiles(collectionID)` paginating on `sinceTime` while `hasMore`
-- [ ] Decrypt per-file key with collection key
-- [ ] Decrypt file metadata blob with file key, expose typed `FileMetadata`
+- [x] `decryptCollection(raw, masterKey)` with key + name decryption, type
+      mapping, isShared flag
+- [x] `decryptFile(raw, collectionKey)` with key + metadata decryption
+      (secretstream blob, not secretbox), fileType mapping, header passthrough
+- [x] `decryptBlob(ciphertext, header, key)` convenience for single-chunk
+      secretstream decryption (used by file metadata and magic metadata)
+- [x] Model types: `Collection`, `EnteFile`, `FileMetadata`, `RawCollection`,
+      `RawEnteFile`
+- [x] Live-tested against real Ente API (collection names + file metadata)
+- [ ] Higher-level `listCollections()` / `listFiles()` with pagination
 
 Phase 6: download