feat: Implement air-gap functionality with timeline impact and evidence snapshot services

- Added AirgapTimelineImpact, AirgapTimelineImpactInput, and AirgapTimelineImpactResult records for managing air-gap bundle import impacts.
- Introduced EvidenceSnapshotRecord, EvidenceSnapshotLinkInput, and EvidenceSnapshotLinkResult records for linking findings to evidence snapshots.
- Created IEvidenceSnapshotRepository interface for managing evidence snapshot records.
- Developed StalenessValidationService to validate staleness and enforce freshness thresholds.
- Implemented AirgapTimelineService for emitting timeline events related to bundle imports.
- Added EvidenceSnapshotService for linking findings to evidence snapshots and verifying their validity.
- Introduced AirGapOptions for configuring air-gap staleness enforcement and thresholds.
- Added minimal jsPDF stub for offline/testing builds in the web application.
- Created TypeScript definitions for jsPDF to enhance type safety in the web application.

docs/risk/samples/explain/SHA256SUMS

@@ -1,4 +1,4 @@
 30a64dcc9fb41d06774a9c125456c212a29915a083cd1d2170f16f343bd0764f  README.md
-4bba11375e9f06942e988dd6cd30e7005fe3b040009b3fffca4e6d36a1875ab3  cli-explain.txt
-22c87e16d5a5cd89f60660eeb07b319989c38f2aa0243da88a312bee1841dda6  console-frame.json
+abcacb431d35d649a0deae81aecce9996b28304da6342a083f9616af6b1ca6a2  cli-explain.txt
+f3f1b41f5261f50f3fc104ebeeb2649cc9866d04f9634228778551e6c3364cb8  console-frame.json
 1d2e56eebf0a266f80519f073e1db532c4a4f2d7fa604ea5c05d4e208719cc7c  explain-trace.json