* .NET: Make Foundry Hosting resilient to missing user identity in local runs
AgentFrameworkResponseHandler threw InvalidOperationException (surfaced as a
500 on every request) when the isolation-key provider returned null, which
always happens locally because the platform x-agent-user-id header is absent.
Running a hosted image outside Foundry therefore failed out of the box.
The handler now branches on FoundryEnvironment.IsHosted: hosted stays strict
(null identity is still a hard error), but non-hosted (local docker run /
dotnet run) tolerates a null identity - per-user isolation is simply not
triggered, the request proceeds with userId null (no partition), and no
hosted context is stamped or validated.
Because local runs no longer need a fallback, the sample-side
DevTemporaryLocalUserIdProvider and AddDevTemporaryLocalContributorSetup are
removed from Hosted_Shared_Contributor_Setup and all sample Program.cs files.
To simulate distinct users locally, send an x-agent-user-id request header;
the default provider reads it exactly as it reads the platform-injected value.
The Memory sample smoke script now drives alice/bob against one container via
that header. AGENT_NAME defaults added to Hosted-ChatClientAgent and
Hosted-MemoryAgent so a hosted deploy (where AGENT_* is a reserved env var)
does not crash at startup.
Updates the two affected unit tests to assert the local-success path and
amends ADR 0031.
* Address review: correct isolation-guarantee and Memory-sample local docs
- AgentFrameworkResponseHandler: note the null/local case is unscoped/shared,
not fully partitioned per user.
- HostedSessionIsolationKeyProvider XML docs: phrase the non-null UserId rule as
a constraint on the returned-context case, since null is now allowed locally.
- Hosted-MemoryAgent: the PerUser() memory scope requires a resolved user, so a
local run needs an x-agent-user-id header; corrected the Program.cs comment
and README (removed the inaccurate "shared bucket locally" claim).
- Test: assert absence of any u-* per-user directory via a wildcard search
rather than checking for a literal "u-" directory.
Roger Barreto
62f0024707