feat(01-01): create email blueprint with encrypted Tortoise ORM models

- Add EncryptedTextField for transparent Fernet encryption
- Create EmailAccount model with encrypted IMAP credentials
- Create EmailSyncStatus model for sync state tracking
- Create Email model with 30-day retention logic
- Follow existing blueprint patterns from users/conversation

blueprints/email/models.py

@@ -0,0 +1,116 @@
+"""
+Database models for email ingestion.
+
+Provides EmailAccount, EmailSyncStatus, and Email models for storing
+IMAP account configuration, sync tracking, and email metadata.
+"""
+
+from datetime import datetime, timedelta
+from tortoise.models import Model
+from tortoise import fields
+
+from .crypto_service import EncryptedTextField
+
+
+class EmailAccount(Model):
+    """
+    Email account configuration for IMAP connections.
+
+    Stores account credentials with encrypted password, connection settings,
+    and account status. Supports multiple accounts per user.
+    """
+
+    id = fields.UUIDField(primary_key=True)
+    user = fields.ForeignKeyField("models.User", related_name="email_accounts")
+
+    # Account identification
+    email_address = fields.CharField(max_length=255, unique=True)
+    display_name = fields.CharField(max_length=255, null=True)
+
+    # IMAP connection settings
+    imap_host = fields.CharField(max_length=255)  # e.g., imap.gmail.com
+    imap_port = fields.IntField(default=993)
+    imap_username = fields.CharField(max_length=255)
+    imap_password = EncryptedTextField()  # Transparently encrypted
+
+    # Account status
+    is_active = fields.BooleanField(default=True)
+    last_error = fields.TextField(null=True)
+
+    # Timestamps
+    created_at = fields.DatetimeField(auto_now_add=True)
+    updated_at = fields.DatetimeField(auto_now=True)
+
+    class Meta:
+        table = "email_accounts"
+
+
+class EmailSyncStatus(Model):
+    """
+    Tracks sync progress and state per email account.
+
+    Maintains last sync timestamp, last processed message UID,
+    and failure tracking to support incremental sync and error handling.
+    """
+
+    id = fields.UUIDField(primary_key=True)
+    account = fields.ForeignKeyField(
+        "models.EmailAccount", related_name="sync_status", unique=True
+    )
+
+    # Sync state tracking
+    last_sync_date = fields.DatetimeField(null=True)
+    last_message_uid = fields.IntField(default=0)  # IMAP UID of last fetched message
+    message_count = fields.IntField(default=0)  # Messages fetched in last sync
+
+    # Error tracking
+    consecutive_failures = fields.IntField(default=0)
+    last_failure_date = fields.DatetimeField(null=True)
+
+    updated_at = fields.DatetimeField(auto_now=True)
+
+    class Meta:
+        table = "email_sync_status"
+
+
+class Email(Model):
+    """
+    Email message metadata and content.
+
+    Stores parsed email data with 30-day retention. Links to ChromaDB
+    for vector search capabilities.
+    """
+
+    id = fields.UUIDField(primary_key=True)
+    account = fields.ForeignKeyField("models.EmailAccount", related_name="emails")
+
+    # Email metadata (RFC822 headers)
+    message_id = fields.CharField(
+        max_length=255, unique=True, index=True
+    )  # RFC822 Message-ID
+    subject = fields.CharField(max_length=500)
+    from_address = fields.CharField(max_length=255)
+    to_address = fields.TextField()  # May contain multiple recipients
+    date = fields.DatetimeField()
+
+    # Email body content
+    body_text = fields.TextField(null=True)  # Plain text version
+    body_html = fields.TextField(null=True)  # HTML version
+
+    # Vector store integration
+    chromadb_doc_id = fields.CharField(
+        max_length=255, null=True
+    )  # Reference to ChromaDB document
+
+    # Retention management
+    created_at = fields.DatetimeField(auto_now_add=True)
+    expires_at = fields.DatetimeField()  # Auto-set to created_at + 30 days
+
+    class Meta:
+        table = "emails"
+
+    async def save(self, *args, **kwargs):
+        """Override save to auto-set expiration date if not provided."""
+        if not self.expires_at:
+            self.expires_at = datetime.now() + timedelta(days=30)
+        await super().save(*args, **kwargs)