Monorepo Integration: Unified Backend, Frontend & Documentation

- Reorganize project into monorepo structure
  - backend/app/ - New FastAPI backend (modular with src/)
  - backend/legacy/ - Legacy database modules (relational & vector)
  - frontend/ - React text editor application

- Add launcher.py for easy full-stack startup
- Complete documentation in README.md
  - Quick start guide
  - API endpoints reference
  - Development setup
  - Troubleshooting

- Refactor main.py to 35 lines (app configuration only)
- Update .gitignore for full-stack project
- Add CHANGELOG.md with version history (v0.1.0-v0.1.1)

Structure is now clean and ready for team collaboration.

backend/legacy/relational_database.py

@@ -0,0 +1,101 @@
+import sqlite3
+import json
+import os
+from fastapi import FastAPI, Body, HTTPException
+from fastapi.middleware.cors import CORSMiddleware
+import uvicorn
+
+app = FastAPI()
+
+app.add_middleware(
+    CORSMiddleware,
+    allow_origins=["*"],
+    allow_methods=["*"],
+    allow_headers=["*"],
+)
+
+BASE_DIR = os.path.dirname(os.path.abspath(__file__))
+DB_FILE = os.path.join(BASE_DIR, "archivium.db")
+
+
+def get_db_connection():
+    conn = sqlite3.connect(DB_FILE)
+    conn.execute("PRAGMA journal_mode=WAL;")
+    conn.row_factory = sqlite3.Row
+    return conn
+
+
+def init_db():
+    with get_db_connection() as conn:
+        conn.execute("""
+                     CREATE TABLE IF NOT EXISTS archive
+                     (
+                         id
+                         INTEGER
+                         PRIMARY
+                         KEY
+                         AUTOINCREMENT,
+                         filename
+                         TEXT
+                         UNIQUE,
+                         ocr_text
+                         TEXT,
+                         metadata
+                         TEXT,
+                         created_at
+                         TIMESTAMP
+                         DEFAULT
+                         CURRENT_TIMESTAMP
+                     )
+                     """)
+        conn.commit()
+
+
+init_db()
+
+
+@app.post("/save-document")
+async def save_document(data: dict = Body(...)):
+    title = data.get("title")
+    content = data.get("content")
+
+    if not title or content is None:
+        raise HTTPException(status_code=400, detail="Missing title or content")
+
+    content_str = json.dumps(content)
+
+    try:
+        with get_db_connection() as conn:
+            conn.execute("""
+                         INSERT INTO archive (filename, ocr_text)
+                         VALUES (?, ?) ON CONFLICT(filename) DO
+                         UPDATE SET
+                             ocr_text=excluded.ocr_text
+                         """, (title, content_str))
+            conn.commit()
+        return {"status": "success"}
+    except Exception as e:
+        raise HTTPException(status_code=500, detail=str(e))
+
+
+@app.get("/load-document")
+async def load_document(title: str = None):
+    with get_db_connection() as conn:
+        if title:
+            row = conn.execute("SELECT filename, ocr_text FROM archive WHERE filename = ?", (title,)).fetchone()
+        else:
+            row = conn.execute("SELECT filename, ocr_text FROM archive ORDER BY id DESC LIMIT 1").fetchone()
+
+    if row:
+        try:
+            content_val = json.loads(row['ocr_text'])
+        except:
+            content_val = row['ocr_text']
+
+        return {"title": row['filename'], "content": content_val}
+
+    raise HTTPException(status_code=404, detail="Document not found")
+
+
+if __name__ == "__main__":
+    uvicorn.run(app, host="127.0.0.1", port=8000)