🛡️ Sentinel: [HIGH] Fix execa environment variable leakage

[google-labs-jules]

🚨 Severity: HIGH
💡 Vulnerability: execa calls without extendEnv: false inherit the unsanitized parent environment, potentially exposing sensitive framework secrets (like API keys) to shell commands and subprocesses in src/cli/authorization/non-interactive.ts and src/core/tools/capability/runner.ts.
🎯 Impact: High impact as this allows spawned commands in various tools/capabilities to capture framework secrets in the environment.
🔧 Fix: Ensure execa is called with extendEnv: false and explicitly pass sanitizeEnvironment(process.env) (or merged process.env) to prevent leakages.
✅ Verification: Tested using custom runner scripts and unit test suite verified (bun run test:full and shell-exec-env.test.ts). Fixed linting issues.

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PR created automatically by Jules for task 5464570045589228060 started by @YoungSx

[google-labs-jules]

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