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.

src/Findings/StellaOps.Findings.Ledger/TASKS.md

@@ -6,7 +6,7 @@
 | LEDGER-34-101 | DONE | Orchestrator export linkage | 2025-11-22 |
 | LEDGER-AIRGAP-56-001 | DONE | Mirror bundle provenance recording | 2025-11-22 |
 
-Status changes must be mirrored in `docs/implplan/SPRINT_0120_0000_0001_policy_reasoning.md`.
+Status changes must be mirrored in `docs/implplan/SPRINT_0120_0001_0001_policy_reasoning.md`.
 
 # Findings Ledger · Sprint 0121-0001-0001