feat: Implement core application structure, AI extraction, persistence, and Telegram bot modules with updated configuration and dependencies.

app/schema/base.py

@@ -0,0 +1,80 @@
+from pydantic import BaseModel, Field
+from typing import Optional, List
+from datetime import datetime, date
+from enum import Enum
+
+
+class ExpenseStatus(str, Enum):
+    """
+    Defines the explicit states an expense can be in throughout its lifecycle.
+    """
+    RECEIVED = "RECEIVED"
+    ANALYZED = "ANALYZED"
+    AWAITING_CONFIRMATION = "AWAITING_CONFIRMATION"
+    CONFIRMED = "CONFIRMED"
+    CORRECTED = "CORRECTED"
+    STORED = "STORED"
+
+class RawInput(BaseModel):
+    """
+    Represents the raw data received from the input source (e.g., n8n).
+    """
+    user_id: str
+    input_type: str = Field(..., alias="type", description="The type of input, e.g., 'text', 'voice', 'image', 'pdf'")
+    data: str
+
+class ExtractedExpense(BaseModel):
+    """
+    Represents an expense after initial data extraction (e.g., from OCR or transcription).
+    Fields are mostly optional as extraction may not be perfect.
+    """
+    provider_name: Optional[str] = None
+    amount: Optional[float] = None
+    currency: Optional[str] = "MXN"
+    expense_date: Optional[date] = None
+    description: Optional[str] = None
+    raw_text: str
+
+class ProvisionalExpense(BaseModel):
+    """
+    Represents a fully processed but unconfirmed expense.
+    This is the state before the user validates the data.
+    """
+    user_id: str
+    extracted_data: ExtractedExpense
+
+    # Classified fields
+    category: Optional[str] = "Por Determinar"
+    subcategory: Optional[str] = None
+    expense_type: Optional[str] = Field(None, alias="tipo_gasto_default", description="e.g., 'personal' or 'negocio'")
+
+    # Metadata
+    confidence_score: float
+    processing_method: str = Field(..., description="How the expense was classified, e.g., 'provider_match', 'keyword_match', 'ai_inference'")
+    validation_notes: List[str] = []
+    status: ExpenseStatus = ExpenseStatus.AWAITING_CONFIRMATION
+    timestamp: datetime = Field(default_factory=datetime.now)
+
+class FinalExpense(BaseModel):
+    """
+    Represents a final, user-confirmed expense record.
+    This is the data that will be stored permanently.
+    """
+    user_id: str
+    provider_name: str
+    amount: float
+    currency: str
+    expense_date: date
+    description: Optional[str] = None
+
+    category: str
+    subcategory: Optional[str] = None
+    expense_type: str
+
+    # Audit trail
+    initial_processing_method: str
+    confirmed_by: str
+    confirmed_at: datetime = Field(default_factory=datetime.now)
+    audit_log: List[str] = []
+
+    status: ExpenseStatus = ExpenseStatus.CONFIRMED