🔧 chore(repo): restructure project file hierarchy

- move project files out of fleetledger directory to root
- update .gitignore to reflect new .env path

📝 docs(README): add detailed project description

- provide an overview of FleetLedger's features and usage
- include setup instructions and security notes

app/models.py

@@ -0,0 +1,99 @@
+from datetime import date, datetime
+from typing import Optional, List
+
+from sqlmodel import SQLModel, Field, Relationship
+
+
+class User(SQLModel, table=True):
+    """Application user model."""
+
+    id: Optional[int] = Field(default=None, primary_key=True)
+
+    username: str = Field(index=True, unique=True)
+    email: Optional[str] = Field(default=None, index=True)
+    password_hash: str
+
+    is_active: bool = Field(default=True)
+    is_admin: bool = Field(default=False)
+
+    servers: List["Server"] = Relationship(back_populates="owner")
+
+
+class Server(SQLModel, table=True):
+    """Server/VPS entry owned by a user."""
+
+    id: Optional[int] = Field(default=None, primary_key=True)
+
+    # Owner
+    owner_id: int = Field(foreign_key="user.id")
+    owner: Optional[User] = Relationship(back_populates="servers")
+
+    # General info
+    name: str
+    hostname: Optional[str] = None
+    type: str = "vps"  # vps, dedicated, storage, managed, other
+    provider: str
+    location: Optional[str] = None
+
+    # Network
+    ipv4: Optional[str] = None
+    ipv6: Optional[str] = None
+
+    # Cost / billing
+    billing_period: str = "monthly"  # monthly, yearly, other
+    price: float = 0.0
+    currency: str = "EUR"
+    contract_start: Optional[date] = None
+    contract_end: Optional[date] = None
+    tags: Optional[str] = None  # e.g. "prod,critical,backup"
+
+    # Hardware
+    cpu_model: Optional[str] = None
+    cpu_cores: Optional[int] = None
+    ram_mb: Optional[int] = None
+    storage_gb: Optional[int] = None
+    storage_type: Optional[str] = None  # nvme, ssd, hdd, ceph, ...
+
+    # Access (no private SSH keys, only hints)
+    mgmt_url: Optional[str] = None
+    mgmt_user: Optional[str] = None
+    mgmt_password_encrypted: Optional[str] = None
+    ssh_user: Optional[str] = None
+    ssh_key_hint: Optional[str] = None  # e.g. "id_ed25519_ovh"
+
+    notes: Optional[str] = None
+
+    created_at: datetime = Field(default_factory=datetime.utcnow)
+    updated_at: datetime = Field(default_factory=datetime.utcnow)
+    archived: bool = Field(default=False)
+
+    # ----- Convenience properties for badges / UI -----
+
+    @property
+    def days_until_contract_end(self) -> Optional[int]:
+        """
+        Number of days until the contract_end date.
+
+        Returns:
+            int: positive or zero if in the future,
+                 negative if already past,
+                 None if no contract_end is set.
+        """
+        if not self.contract_end:
+            return None
+        return (self.contract_end - date.today()).days
+
+    @property
+    def is_expired(self) -> bool:
+        """Return True if the contract_end date lies in the past."""
+        return self.contract_end is not None and self.contract_end < date.today()
+
+    @property
+    def is_expiring_soon(self) -> bool:
+        """
+        Return True if the contract will end within the next 30 days.
+
+        This is used for "expiring soon" badges in the UI.
+        """
+        days = self.days_until_contract_end
+        return days is not None and 0 <= days <= 30