Update admin theme/layout and refresh README details.

Align the project baseline with the latest admin interface styling and layout structure while documenting setup and usage updates in README.

apps/api/app/modules/content/router.py

@@ -0,0 +1,56 @@
+from fastapi import APIRouter, Depends, HTTPException
+
+from app.core.dependencies import require_admin
+from app.modules.content.schemas import ContentPageIn, ContentPagePatchIn
+from app.modules.content.service import (
+    create_page,
+    delete_page,
+    get_page_by_slug,
+    list_all_pages,
+    list_published_pages,
+    page_exists,
+    page_to_dict,
+    update_page,
+)
+
+router = APIRouter()
+
+
+@router.get("/pages")
+async def list_pages_route():
+    pages = list_published_pages()
+    return {"data": [page_to_dict(page) for page in pages]}
+
+
+@router.get("/pages/manage/all")
+async def list_all_pages_route(_admin=Depends(require_admin)):
+    pages = list_all_pages()
+    return {"data": [page_to_dict(page) for page in pages]}
+
+
+@router.get("/pages/{slug}")
+async def get_page_route(slug: str):
+    page = get_page_by_slug(slug)
+    if not page:
+        raise HTTPException(status_code=404, detail="PAGE_NOT_FOUND")
+    return page_to_dict(page)
+
+
+@router.post("/pages")
+async def create_page_route(payload: ContentPageIn, admin=Depends(require_admin)):
+    page = create_page(payload.slug, payload.title, payload.body, payload.status, admin.id)
+    return page_to_dict(page)
+
+
+@router.patch("/pages/{page_id}")
+async def update_page_route(page_id: str, payload: ContentPagePatchIn, _admin=Depends(require_admin)):
+    if not page_exists(page_id):
+        raise HTTPException(status_code=404, detail="PAGE_NOT_FOUND")
+    page = update_page(page_id, payload.title, payload.body, payload.status)
+    return page_to_dict(page)
+
+
+@router.delete("/pages/{page_id}")
+async def delete_page_route(page_id: str, _admin=Depends(require_admin)):
+    delete_page(page_id)
+    return {"message": "deleted"}