chore(01-01): add FERNET_KEY config and email tables migration

- Add FERNET_KEY to .env.example with generation instructions
- Register email.models in aerich_config.py and app.py
- Register email blueprint in app.py
- Create database migration for email_accounts, email_sync_status, emails
- Migration includes proper foreign keys and indexes

migrations/models/2_20260208091453_add_email_tables.py

@@ -0,0 +1,56 @@
+from tortoise import BaseDBAsyncClient
+
+RUN_IN_TRANSACTION = True
+
+
+async def upgrade(db: BaseDBAsyncClient) -> str:
+    return """
+        CREATE TABLE IF NOT EXISTS "email_accounts" (
+    "id" UUID NOT NULL PRIMARY KEY,
+    "email_address" VARCHAR(255) NOT NULL UNIQUE,
+    "display_name" VARCHAR(255),
+    "imap_host" VARCHAR(255) NOT NULL,
+    "imap_port" INT NOT NULL DEFAULT 993,
+    "imap_username" VARCHAR(255) NOT NULL,
+    "imap_password" TEXT NOT NULL,
+    "is_active" BOOL NOT NULL DEFAULT TRUE,
+    "last_error" TEXT,
+    "created_at" TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "updated_at" TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "user_id" UUID NOT NULL REFERENCES "users" ("id") ON DELETE CASCADE
+);
+CREATE TABLE IF NOT EXISTS "email_sync_status" (
+    "id" UUID NOT NULL PRIMARY KEY,
+    "last_sync_date" TIMESTAMPTZ,
+    "last_message_uid" INT NOT NULL DEFAULT 0,
+    "message_count" INT NOT NULL DEFAULT 0,
+    "consecutive_failures" INT NOT NULL DEFAULT 0,
+    "last_failure_date" TIMESTAMPTZ,
+    "updated_at" TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "account_id" UUID NOT NULL UNIQUE REFERENCES "email_accounts" ("id") ON DELETE CASCADE
+);
+CREATE TABLE IF NOT EXISTS "emails" (
+    "id" UUID NOT NULL PRIMARY KEY,
+    "message_id" VARCHAR(255) NOT NULL UNIQUE,
+    "subject" VARCHAR(500) NOT NULL,
+    "from_address" VARCHAR(255) NOT NULL,
+    "to_address" TEXT NOT NULL,
+    "date" TIMESTAMPTZ NOT NULL,
+    "body_text" TEXT,
+    "body_html" TEXT,
+    "chromadb_doc_id" VARCHAR(255),
+    "created_at" TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    "expires_at" TIMESTAMPTZ NOT NULL,
+    "account_id" UUID NOT NULL REFERENCES "email_accounts" ("id") ON DELETE CASCADE
+);
+CREATE INDEX IF NOT EXISTS "idx_emails_message_9e3c0c" ON "emails" ("message_id");"""
+
+
+async def downgrade(db: BaseDBAsyncClient) -> str:
+    return """
+        DROP TABLE IF EXISTS "emails";
+        DROP TABLE IF EXISTS "email_sync_status";
+        DROP TABLE IF EXISTS "email_accounts";"""
+
+
+MODELS_STATE = ""