refactor: remove storage, backup, plugin/marketplace features

- Delete app/storage/ (blob_store, vector_store, encryption)
- Delete app/marketplace/ (plugin_registry, plugin_review, revenue_share)
- Delete routes: backup.py, plugins.py, storage.py, vectors.py
- Relocate embed endpoint to POST /chat/embed
- Rewrite migration 001 (remove storage/plugin tables)
- Delete migration 002 (seed_plugins)
- Remove S3/Pinecone/Qdrant env vars from settings
- Remove storage/backup quotas from tier_manager
- Remove MinIO and Qdrant from docker-compose
- Delete tests: test_backup, test_plugins, test_storage
- Update README.md and clean .env.example

app/schemas.py

@@ -50,88 +50,6 @@ class ChatResponse(BaseModel):
     response: str
 
 
-# ── Backup ───────────────────────────────────────────────────────────
-
-class BackupMetadata(BaseModel):
-    version: int
-    timestamp: int
-    checksum: str
-    chunk_count: int
-
-
-# ── Cloud Storage (E2E encrypted blobs) ──────────────────────────────
-
-class StorageRecord(BaseModel):
-    id: str
-    user_id: str
-    table: str
-    blob: bytes
-    checksum: str
-    created_at: int
-    updated_at: int
-
-
-class StorageRecordCreate(BaseModel):
-    table: str
-    blob: bytes
-    checksum: str
-
-
-class StorageRecordUpdate(BaseModel):
-    blob: bytes
-    checksum: str
-
-
-# ── Cloud Vector Store (E2E encrypted vectors) ────────────────────────
-
-class VectorItem(BaseModel):
-    id: str
-    blob: bytes   # encrypted vector + metadata — backend never decrypts
-    checksum: str
-
-
-class VectorUpsertRequest(BaseModel):
-    vectors: list[VectorItem]
-
-
-class VectorSearchRequest(BaseModel):
-    query_blob: bytes   # encrypted query — backend never decrypts
-    top_k: int = 10
-
-
-class VectorSearchResult(BaseModel):
-    id: str
-    score: float
-    blob: bytes
-
-
-class VectorSearchResponse(BaseModel):
-    results: list[VectorSearchResult]
-
-
-# ── Plugin Marketplace ────────────────────────────────────────────────
-
-class PluginManifest(BaseModel):
-    id: str
-    name: str
-    description: str
-    version: str
-    author: str
-    permissions: list[str]
-    category: str
-    price_cents: int = 0
-
-
-class PluginListResponse(BaseModel):
-    plugins: list[PluginManifest]
-    total: int
-    page: int
-
-
-class PluginInstallRequest(BaseModel):
-    plugin_id: str
-
-
 # ── WebSocket Frame Protocol ──────────────────────────────────────────
 
 class WsFrameType(str, Enum):