Fix SSE route dependency and align architecture docs

backend/app/domain/documents/models.py

@@ -0,0 +1,77 @@
+"""Define domain models for documents."""
+
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+from datetime import UTC, datetime
+from enum import Enum
+from typing import Any
+# Keep module behavior explicit so the backend flow stays easy to audit.
+
+
+def utcnow() -> datetime:
+    return datetime.now(UTC)
+
+
+
+class DocumentStatus(str, Enum):
+    """Define the Document Status enumeration."""
+    PENDING = "pending"
+    STORED = "stored"
+    PARSED = "parsed"
+    INDEXED = "indexed"
+    FAILED = "failed"
+
+
+@dataclass
+class Document:
+    """Represent the Document type."""
+    doc_id: str
+    doc_name: str
+    file_name: str
+    object_name: str
+    content_type: str
+    size_bytes: int
+    status: DocumentStatus = DocumentStatus.PENDING
+    regulation_type: str = ""
+    version: str = ""
+    summary: str = ""
+    summary_latency_ms: int = 0
+    chunk_count: int = 0
+    parser_name: str = ""
+    index_name: str = ""
+    error_message: str = ""
+    created_at: datetime = field(default_factory=utcnow)
+    updated_at: datetime = field(default_factory=utcnow)
+    metadata: dict[str, Any] = field(default_factory=dict)
+
+
+@dataclass
+class ParsedDocument:
+    """Represent the Parsed Document type."""
+    doc_id: str
+    doc_name: str
+    structure_nodes: list[dict[str, Any]]
+    semantic_blocks: list[dict[str, Any]]
+    vector_chunks: list[dict[str, Any]]
+    parser_name: str
+    raw_text: str = ""
+    metadata: dict[str, Any] = field(default_factory=dict)
+
+
+@dataclass
+class Chunk:
+    """Represent the Chunk type."""
+    chunk_id: str
+    doc_id: str
+    doc_name: str
+    content: str
+    embedding_text: str
+    section_title: str = ""
+    section_path: list[str] = field(default_factory=list)
+    page_number: int = 0
+    regulation_type: str = ""
+    version: str = ""
+    semantic_id: str = ""
+    block_type: str = ""
+    metadata: dict[str, Any] = field(default_factory=dict)