feat: add CSP checks component

[OWConnoi]

Summary

• add a new shipsec.csp.check inline security component for issue CSP Checks Component #18
• support checking live target URLs or analyzing headers from the existing HTTP Request component without refetching
• emit structured CSP findings, checked target metadata, and analytics-ready results for the Analytics Sink

Closes #18

Verification

• npx -y bun@1.1.20 test src/components/security/__tests__/csp-checks.test.ts
• npx -y bun@1.1.20 run lint from worker/
• npx -y bun@1.1.20 run typecheck from repo root
• git diff --check

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