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/users/router.py

@@ -0,0 +1,59 @@
+from fastapi import APIRouter, Depends, File, HTTPException, Request, UploadFile
+
+from app.core.dependencies import get_current_user
+from app.core.media_signing import build_signed_media_url
+from app.core.redis import check_rate_limit
+from app.modules.media.service import AvatarValidationError
+from app.modules.users.schemas import PasswordChangeIn, UserPatchIn
+from app.modules.users.service import change_password, get_me, update_me, upload_avatar
+
+router = APIRouter()
+
+
+def _profile_response(data: dict) -> dict:
+    return {
+        "user": {
+            "id": data["user"].id,
+            "email": data["user"].email,
+            "role": data["user"].role,
+            "status": data["user"].status,
+        },
+        "profile": {
+            "display_name": data["profile"].display_name,
+            "avatar_url": build_signed_media_url(data["profile"].avatar_url),
+        },
+    }
+
+
+@router.get("/me")
+async def me_route(current_user=Depends(get_current_user)):
+    return _profile_response(get_me(current_user))
+
+
+@router.patch("/me")
+async def patch_me_route(payload: UserPatchIn, current_user=Depends(get_current_user)):
+    return _profile_response(update_me(current_user, payload.display_name))
+
+
+@router.post("/me/password")
+async def change_password_route(payload: PasswordChangeIn, current_user=Depends(get_current_user)):
+    try:
+        change_password(current_user, payload.current_password, payload.new_password)
+    except ValueError:
+        raise HTTPException(status_code=400, detail="INVALID_CURRENT_PASSWORD")
+    return {"message": "password_changed"}
+
+
+@router.post("/me/avatar")
+async def upload_avatar_route(
+    request: Request,
+    file: UploadFile = File(...),
+    current_user=Depends(get_current_user),
+):
+    check_rate_limit(f"avatar:{current_user.id}", limit=10, window_seconds=3600)
+    content = await file.read()
+    try:
+        data = upload_avatar(current_user, content)
+    except AvatarValidationError as exc:
+        raise HTTPException(status_code=400, detail=str(exc))
+    return _profile_response(data)