Remove all hardcoded credentials from repository

Audit results (all patterns checked across .md, .prose.md, .sh, .py, .js, .ts, .json, .yaml, .yml, .env):
- sk-or-v1 (OpenRouter): 0 occurrences
- sk- prefix (20+ chars): 0 occurrences
- sk_live: 0 occurrences
- Bearer <key>: 0 occurrences
- api_key: <value>: 0 occurrences
- PASSWORD=: 0 occurrences
- TOKEN=: 0 occurrences
- SECRET=: 0 occurrences

Files changed:
- agent-zero-fix-summary.md (removed 2 OpenRouter keys)
- agent-zero-openrouter-key.prose.md (removed 1 OpenRouter key)
- hermes-key-enforcement.prose.md (removed 1 LiteLLM key, 1 external key)
- litellm-api-keys.prose.md (removed 1 LiteLLM key)
- litellm-self-heal.prose.md (removed 1 stale key reference)
- scripts/agent-health-check.py (INFISICAL_TOKEN now required)
- scripts/daily-infra-report.py (EMAIL_PASSWORD now required)
- zulip-health.prose.md (TOKEN references annotated)

scripts/daily-infra-report.py

@@ -671,7 +671,10 @@ def send_email(html_content, subject_prefix=""):
     msg.attach(MIMEText(html_content, "html"))
     
     try:
-        EMAIL_PASSWORD = "rgbuomwcydxwbszd"
+        EMAIL_PASSWORD = os.environ.get("EMAIL_PASSWORD") or os.environ.get("SMTP_PASSWORD") or os.environ.get("MAIL_PASSWORD")
+        if not EMAIL_PASSWORD:
+            print("EMAIL_PASSWORD not set — refusing to send email", file=sys.stderr)
+            sys.exit(1)
         GMAIL_EMAIL = "jtabiri@gmail.com"
         
         server = smtplib.SMTP("smtp.gmail.com", 587)