refactor: 前端架构重构 - 提取 CSS 和逻辑到独立模块

前端重构：
- 删除旧的大体积 Vue 组件（HomeView, FileManage, TextSplit 等）
- 删除旧的 composables（useFormatters, useModels, useProjects）
- 新增 core/, page-logic/, pages/, shared/ 模块化目录结构
- 提取 CSS 到 styles/pages/ 目录
- 添加全局样式 variables.css 和 common.css

后端 API 更新：
- chunks: 语义分割 API 增强
- files: 文件处理 API 更新
- models: 模型管理 API 更新
- questions: 问答管理 API 更新
- database: 数据库连接优化
- semantic_embedding: 语义嵌入服务优化

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/app/api/v1/files/__init__.py

@@ -9,6 +9,7 @@ from uuid import UUID, uuid4
 from fastapi import APIRouter, Depends, UploadFile, File, Query
 from fastapi.responses import FileResponse, PlainTextResponse
 from sqlalchemy.ext.asyncio import AsyncSession
+from sqlalchemy import select
 
 from app.api.response import ApiResponse, PaginatedResponse
 from app.core.config import get_settings
@@ -17,6 +18,7 @@ from app.core.exceptions import ValidationException, NotFoundException
 from app.core.crud import CRUDBase
 from app.core.logging import log_success, log_failure
 from app.models.models import File as FileModel
+from app.models.models import Chunk, Question
 from app.schemas.file import FileResponse, FileCreateSchema
 from markitdown import MarkItDown
 
@@ -329,11 +331,27 @@ async def delete_file(
     file_id: UUID,
     db: AsyncSession = Depends(get_db)
 ):
-    """Delete file"""
+    """Delete file and all related data (markdown, chunks, questions)"""
     file = await file_crud.get(db, file_id)
     if not file or file.project_id != project_id:
         raise NotFoundException("File", file_id)
 
+    # Delete related chunks and their questions (explicit deletion for safety)
+    chunks_result = await db.execute(
+        select(Chunk).where(Chunk.file_id == file_id)
+    )
+    chunks = chunks_result.scalars().all()
+    for chunk in chunks:
+        # Delete questions related to this chunk
+        questions_result = await db.execute(
+            select(Question).where(Question.chunk_id == chunk.id)
+        )
+        questions = questions_result.scalars().all()
+        for question in questions:
+            await db.delete(question)
+        # Delete chunk
+        await db.delete(chunk)
+
     # Delete file from raw directory
     if file.file_path and os.path.exists(file.file_path):
         await asyncio.get_event_loop().run_in_executor(
@@ -342,16 +360,27 @@ async def delete_file(
             file.file_path
         )
 
-    # Delete file from ready directory (processed markdown)
-    ready_path = Path("/data/code/YG-Datasets/data") / str(project_id) / "ready" / f"{file_id}.md"
-    if ready_path.exists():
-        await asyncio.get_event_loop().run_in_executor(
-            None,
-            os.remove,
-            str(ready_path)
-        )
+    # Delete file from ready directory (processed markdown) - try both naming conventions
+    ready_dir = Path("/data/code/YG-Datasets/data") / str(project_id) / "ready"
+    if ready_dir.exists():
+        # Try file_id.md (from upload process)
+        ready_path = ready_dir / f"{file_id}.md"
+        if ready_path.exists():
+            await asyncio.get_event_loop().run_in_executor(
+                None,
+                os.remove,
+                str(ready_path)
+            )
+        # Try file_id_filename.md (from split process)
+        for md_file in ready_dir.glob(f"{file_id}_*.md"):
+            await asyncio.get_event_loop().run_in_executor(
+                None,
+                os.remove,
+                str(md_file)
+            )
 
     await file_crud.delete(db, file_id)
+    await db.commit()
     return ApiResponse.ok(message="File deleted successfully")