fix(config): harden bootstrap logic and add email E2E test

Harden bootstrap_db_config to prioritize .env settings for core infrastructure (DB/SMTP) and only use DB values if placeholders are detected or values have explicitly changed. Added test_e2e_email_send.py for functional SMTP verification.

tests/e2e/test_e2e_email_send.py

@@ -0,0 +1,48 @@
+import requests
+import json
+import time
+
+# --- Configuration ---
+API_BASE = "https://dev-api.oneskyit.com/util/email"
+API_KEY = "PMM4n50teUCaOMMTN8qOJA" # Agent API Key
+ACCOUNT_ID = "_XY7DXtc9MY" # Standard Test Account
+
+def test_email_send_live():
+    """
+    End-to-End test for the email send utility.
+    Verifies that the API can successfully authenticate with SMTP and dispatch an email.
+    """
+    print("\n--- Testing Live Email Send via API ---")
+    print(f"Target: {API_BASE}/send")
+    
+    payload = {
+        "from_email": "noreply@oneskyit.com",
+        "from_name": "Aether API Monitor",
+        "to_email": "scott.idem+devtest@oneskyit.com",
+        "to_name": "Scott Idem (Dev Test)",
+        "subject": f"Aether E2E Test: {time.strftime('%Y-%m-%d %H:%M:%S')}",
+        "body_html": "<h3>Aether API Status Check</h3><p>This email confirms that the SMTP subsystem is operational and prioritizing correctly.</p><p>Environment: <b>Development</b></p>",
+        "body_text": "Aether API Status Check: SMTP subsystem is operational."
+    }
+    
+    headers = {
+        "Content-Type": "application/json",
+        "X-Aether-API-Key": API_KEY,
+        "x-account-id": ACCOUNT_ID
+    }
+    
+    start_time = time.time()
+    resp = requests.post(f"{API_BASE}/send", headers=headers, json=payload)
+    duration = time.time() - start_time
+    
+    print(f"Status Code: {resp.status_code}")
+    print(f"Response:    {resp.text}")
+    print(f"Duration:    {duration:.2f}s")
+    
+    if resp.status_code == 200:
+        print("[✅ PASS] Email successfully dispatched.")
+    else:
+        print("[❌ FAIL] Email failed to send. Check FastAPI logs for SMTP errors.")
+
+if __name__ == "__main__":
+    test_email_send_live()