Replace bare re-export in investigation-storage.js with explicit wrapper
functions that own the canonical identity contract: snapshot.id is the sole
save identity authority. The provider never allocates or changes IDs.
7 new deterministic tests prove: identified snapshots persist under their
own id key, explicit competing id arguments are ignored, A/B remain
independently addressable, unknown IDs return null, and legacy singleton
compatibility is preserved for unmigrated callers.
No application callers modified. UI/routes not migrated.
- loadInvestigation(id) selects by durable ID when provided, null for unknown
- saveInvestigation(snapshot, id) persists under provider-chosen key derived from id
- clearInvestigation(id) removes specific investigation by identity when provided
- localStorage representation: confidence-engine-investigation:<durable-id>
- Backward-compatible singleton path preserved for existing unmigrated callers
- 6 new targeted tests proving two independently addressable Investigations
robbond