Add profile feature, input sanitization, and stronger security checks

Backend:
- app/core/sanitize.py: shared sanitize_str, normalize_email, validate_phone,
  validate_date_of_birth — applied to every user-supplied DB-bound input
- app/schemas/user.py: sanitize full_name, normalize email on UserCreate
- app/models/profile.py: profiles table (position, phone, dob, address, updated_at)
- app/models/user.py: Profile back-ref, is_superuser admin-role comment
- app/schemas/profile.py: ProfileRead/ProfileUpdate with full sanitization
- app/routers/profile.py: GET+PUT /api/profile/me (lazy profile creation)
- app/main.py: register /api/profile router
- alembic migration 676084df61d1: create profiles table

Frontend:
- components/Nav.tsx: shared nav (Dashboard | Profile | Logout)
- pages/ProfilePage.tsx: profile view + inline edit form with error handling
- pages/DashboardPage.tsx: use Nav component
- api/client.ts: ProfileData type, getProfile, updateProfile
- App.tsx: /profile private route

Security:
- scripts/security_check.py: tighter SQL injection patterns (f-string/format/%
  in execute/query/text()), new SANIT category for raw request→DB patterns

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

backend/alembic/versions/676084df61d1_add_profiles_table.py

@@ -0,0 +1,40 @@
+"""add profiles table
+
+Revision ID: 676084df61d1
+Revises: 38efeff7c45a
+Create Date: 2026-04-13 16:11:46.705481
+
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+
+revision: str = '676084df61d1'
+down_revision: Union[str, None] = '38efeff7c45a'
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.create_table('profiles',
+    sa.Column('id', sa.String(), nullable=False),
+    sa.Column('user_id', sa.String(), nullable=False),
+    sa.Column('phone', sa.String(length=20), nullable=True),
+    sa.Column('date_of_birth', sa.Date(), nullable=True),
+    sa.Column('position', sa.String(length=128), nullable=True),
+    sa.Column('address', sa.String(length=255), nullable=True),
+    sa.Column('updated_at', sa.DateTime(timezone=True), server_default=sa.text('now()'), nullable=False),
+    sa.ForeignKeyConstraint(['user_id'], ['users.id'], ondelete='CASCADE'),
+    sa.PrimaryKeyConstraint('id'),
+    sa.UniqueConstraint('user_id')
+    )
+    # ### end Alembic commands ###
+
+
+def downgrade() -> None:
+    # ### commands auto generated by Alembic - please adjust! ###
+    op.drop_table('profiles')
+    # ### end Alembic commands ###

backend/app/core/sanitize.py

@@ -0,0 +1,74 @@
+"""
+Input sanitization utilities.
+
+Every string that originates from user input and is destined for the database
+MUST pass through these helpers before reaching a SQLAlchemy model or query.
+SQLAlchemy's ORM already uses bound parameters (no raw SQL), so these helpers
+address the layer above: ensuring data is well-formed, length-capped, and free
+of null bytes or control characters before it is stored.
+"""
+
+import re
+import unicodedata
+from datetime import date
+
+# ── Constants ─────────────────────────────────────────────────────────────────
+
+_PHONE_RE = re.compile(r"^\+?[\d\s\-()\[\]]{7,20}$")
+
+# ── Core helper ───────────────────────────────────────────────────────────────
+
+
+def sanitize_str(value: str | None, max_len: int = 255) -> str | None:
+    """Strip whitespace, reject null bytes and non-printable control characters,
+    enforce a maximum length.  Returns None unchanged so optional fields work
+    naturally with ``Optional[str]`` annotations."""
+    if value is None:
+        return None
+
+    # Strip leading/trailing whitespace
+    value = value.strip()
+
+    # Reject null bytes (common injection vector)
+    if "\x00" in value:
+        raise ValueError("Input must not contain null bytes")
+
+    # Reject ASCII control characters (0x01–0x1F, 0x7F) except tab/newline/CR
+    # which may appear in multi-line fields.  Use Unicode category 'Cc'.
+    for ch in value:
+        if unicodedata.category(ch) == "Cc" and ch not in ("\t", "\n", "\r"):
+            raise ValueError("Input contains invalid control characters")
+
+    if len(value) > max_len:
+        raise ValueError(f"Input must not exceed {max_len} characters")
+
+    return value if value != "" else None
+
+
+def normalize_email(value: str) -> str:
+    """Lowercase and strip an email address."""
+    return value.strip().lower()
+
+
+def validate_phone(value: str | None) -> str | None:
+    """Sanitize then validate phone number format."""
+    value = sanitize_str(value, max_len=20)
+    if value is None:
+        return None
+    if not _PHONE_RE.match(value):
+        raise ValueError(
+            "Phone number may only contain digits, spaces, +, -, (, ) and [ ] "
+            "and must be 7–20 characters"
+        )
+    return value
+
+
+def validate_date_of_birth(value: date | None) -> date | None:
+    """Reject obviously invalid birth dates (before 1900 or in the future)."""
+    if value is None:
+        return None
+    if value.year < 1900:
+        raise ValueError("Date of birth must be 1900 or later")
+    if value > date.today():
+        raise ValueError("Date of birth must not be in the future")
+    return value

backend/app/main.py

@@ -2,7 +2,7 @@ from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
 
 from app.core.config import settings
-from app.routers import auth, users
+from app.routers import auth, profile, users
 
 app = FastAPI(title=settings.PROJECT_NAME, version="0.1.0")
 
@@ -16,6 +16,7 @@ app.add_middleware(
 
 app.include_router(auth.router, prefix="/api/auth", tags=["auth"])
 app.include_router(users.router, prefix="/api/users", tags=["users"])
+app.include_router(profile.router, prefix="/api/profile", tags=["profile"])
 
 
 @app.get("/api/health")

backend/app/models/__init__.py

@@ -1,3 +1,4 @@
+from app.models.profile import Profile
 from app.models.user import User
 
-__all__ = ["User"]
+__all__ = ["User", "Profile"]

backend/app/models/profile.py

@@ -0,0 +1,34 @@
+import uuid
+from datetime import date, datetime
+
+from sqlalchemy import Date, DateTime, ForeignKey, String, func
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.database import Base
+
+
+class Profile(Base):
+    __tablename__ = "profiles"
+
+    id: Mapped[str] = mapped_column(
+        String, primary_key=True, default=lambda: str(uuid.uuid4())
+    )
+    # One-to-one with users; deleting a user cascades to the profile.
+    user_id: Mapped[str] = mapped_column(
+        String, ForeignKey("users.id", ondelete="CASCADE"), unique=True, nullable=False
+    )
+
+    phone: Mapped[str | None] = mapped_column(String(20), nullable=True)
+    date_of_birth: Mapped[date | None] = mapped_column(Date, nullable=True)
+    # Job title / role within the organisation (e.g. "Software Engineer", "HR Manager").
+    position: Mapped[str | None] = mapped_column(String(128), nullable=True)
+    address: Mapped[str | None] = mapped_column(String(255), nullable=True)
+
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True),
+        server_default=func.now(),
+        onupdate=func.now(),
+        nullable=False,
+    )
+
+    user = relationship("User", back_populates="profile")

backend/app/models/user.py

@@ -1,10 +1,14 @@
 import uuid
+from typing import TYPE_CHECKING
 
 from sqlalchemy import Boolean, String
-from sqlalchemy.orm import Mapped, mapped_column
+from sqlalchemy.orm import Mapped, mapped_column, relationship
 
 from app.database import Base
 
+if TYPE_CHECKING:
+    from app.models.profile import Profile
+
 
 class User(Base):
     __tablename__ = "users"
@@ -14,4 +18,10 @@ class User(Base):
     hashed_password: Mapped[str] = mapped_column(String, nullable=False)
     full_name: Mapped[str] = mapped_column(String, nullable=True)
     is_active: Mapped[bool] = mapped_column(Boolean, default=True)
+    # Role flag — True = admin, False = regular user.
+    # Never exposed in API responses; set only by direct DB or admin tooling.
     is_superuser: Mapped[bool] = mapped_column(Boolean, default=False)
+
+    profile: Mapped["Profile"] = relationship(
+        "Profile", back_populates="user", uselist=False, cascade="all, delete-orphan"
+    )

backend/app/routers/profile.py

@@ -0,0 +1,48 @@
+from fastapi import APIRouter, Depends
+from sqlalchemy import select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from app.database import get_db
+from app.deps import get_current_user
+from app.models.profile import Profile
+from app.models.user import User
+from app.schemas.profile import ProfileRead, ProfileUpdate
+
+router = APIRouter()
+
+
+async def _get_or_create_profile(user: User, db: AsyncSession) -> Profile:
+    """Return the user's profile, creating an empty one on first access."""
+    result = await db.execute(select(Profile).where(Profile.user_id == user.id))
+    profile = result.scalar_one_or_none()
+    if profile is None:
+        profile = Profile(user_id=user.id)
+        db.add(profile)
+        await db.commit()
+        await db.refresh(profile)
+    return profile
+
+
+@router.get("/me", response_model=ProfileRead)
+async def get_my_profile(
+    current_user: User = Depends(get_current_user),
+    db: AsyncSession = Depends(get_db),
+) -> Profile:
+    return await _get_or_create_profile(current_user, db)
+
+
+@router.put("/me", response_model=ProfileRead)
+async def update_my_profile(
+    body: ProfileUpdate,
+    current_user: User = Depends(get_current_user),
+    db: AsyncSession = Depends(get_db),
+) -> Profile:
+    profile = await _get_or_create_profile(current_user, db)
+
+    # Only update fields that were explicitly provided in the request body.
+    for field, value in body.model_dump(exclude_unset=True).items():
+        setattr(profile, field, value)
+
+    await db.commit()
+    await db.refresh(profile)
+    return profile

backend/app/schemas/profile.py

@@ -0,0 +1,44 @@
+from datetime import date, datetime
+
+from pydantic import BaseModel, field_validator
+
+from app.core.sanitize import sanitize_str, validate_date_of_birth, validate_phone
+
+
+class ProfileRead(BaseModel):
+    id: str
+    user_id: str
+    phone: str | None
+    date_of_birth: date | None
+    position: str | None
+    address: str | None
+    updated_at: datetime
+
+    model_config = {"from_attributes": True}
+
+
+class ProfileUpdate(BaseModel):
+    phone: str | None = None
+    date_of_birth: date | None = None
+    position: str | None = None
+    address: str | None = None
+
+    @field_validator("phone", mode="before")
+    @classmethod
+    def clean_phone(cls, v: str | None) -> str | None:
+        return validate_phone(v)
+
+    @field_validator("position", mode="before")
+    @classmethod
+    def clean_position(cls, v: str | None) -> str | None:
+        return sanitize_str(v, max_len=128)
+
+    @field_validator("address", mode="before")
+    @classmethod
+    def clean_address(cls, v: str | None) -> str | None:
+        return sanitize_str(v, max_len=255)
+
+    @field_validator("date_of_birth", mode="after")
+    @classmethod
+    def clean_dob(cls, v: date | None) -> date | None:
+        return validate_date_of_birth(v)

backend/app/schemas/user.py

@@ -2,6 +2,8 @@ import re
 
 from pydantic import BaseModel, EmailStr, field_validator
 
+from app.core.sanitize import normalize_email, sanitize_str
+
 # Common words that must not appear as whole words inside a password.
 # Checked case-insensitively with word boundaries.
 _FORBIDDEN_WORDS = {
@@ -45,6 +47,16 @@ class UserCreate(BaseModel):
     password: str
     full_name: str | None = None
 
+    @field_validator("email", mode="before")
+    @classmethod
+    def normalize_email_field(cls, v: str) -> str:
+        return normalize_email(v)
+
+    @field_validator("full_name", mode="before")
+    @classmethod
+    def sanitize_full_name(cls, v: str | None) -> str | None:
+        return sanitize_str(v, max_len=128)
+
     @field_validator("password")
     @classmethod
     def password_strength(cls, v: str) -> str: