fix(conversations): read message history stored as jsonb - #337

filter-codeql-sarif: removed 3797 of 4382 result(s) in .NET source-generator output, kept 585 — by generator: System.Text.Json.SourceGeneration 3519, Microsoft.AspNetCore.Http.RequestDelegateGenerator 227, System.Text.RegularExpressions.Generator 25, Microsoft.Extensions.Configuration.Binder.SourceGeneration 13, Microsoft.AspNetCore.OpenApi.SourceGenerators 8, Microsoft.Extensions.Logging.Generators 5; by rule: cs/useless-cast-to-self 3366, cs/useless-upcast 160, cs/nested-if-statements 134, cs/useless-assignment-to-local 116, cs/self-assignment 8, cs/local-shadows-member 5, cs/catch-of-all-exceptions 3, cs/constant-condition 2, cs/linq/missed-select 2, cs/linq/missed-where 1. Wrote /home/runner/work/_temp/codeql-sarif-filtered/csharp.sarif.