🛡️ Sentinel: [CRITICAL] 누락된 비밀 토큰 마스킹 (Redaction) 추가

[seonghobae]

This PR fixes a security issue where newly added secret scanning rules (such as AWS access keys, GitHub tokens, Anthropic API keys, etc.) were correctly detected by the scanner, but their corresponding identifying tokens were missing from the _SENSITIVE_RULE_TOKENS tuple in scanner/cli/appguardrail.py.

Because of this omission, if the scanner found one of these secrets, it would not recognize the rule as a "sensitive rule" and could potentially print the actual secret value in the terminal output or CI/CD logs.

By adding "aws", "private-key", "anthropic", "google", "github", and "api-key" to _SENSITIVE_RULE_TOKENS, any output from these rules will now be safely redacted as [REDACTED: sensitive match suppressed]. A note was also added to the Sentinel journal (.jules/sentinel.md) about this learning.

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PR created automatically by Jules for task 3644730199513356947 started by @seonghobae

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