* Add per-agent and per-user session storage isolation for Foundry Hosting
Partitions hosted session and checkpoint files as {root}/a-{agentName}/u-{userId}/c-{contextId}.json so a container that serves multiple agents and multiple users cannot leak state across tenants. The user layer collapses to a-{agent}/c-{conv}.json when no x-agent-user-id is present (raw local). Adds a reject-style path-traversal guard (CWE-22) for the untrusted user id plus a resolve-and-assert-under-root containment check, and keeps the strict-resume 403 identity check as a second defense layer.
AgentSessionStore.GetSessionAsync/SaveSessionAsync take a required (nullable) userId so a caller can never silently persist a session unscoped; the handler resolves the user id before loading the session and threads it to both. Tool approvals ride in the session checkpoint (ToolApprovalIdMap to AgentSessionStateBag), so the partitioned path covers them and no separate approval store is needed. Renames the sample HOSTED_USER_ISOLATION_KEY env var to HOSTED_USER_ID and DevTemporaryLocalSessionIsolationKeyProvider to DevTemporaryLocalUserIdProvider. Documents the design in ADR 0031. Adds handler-driven multi-agent/multi-user file-system tests and store-level traversal/isolation tests.
* Fail fast with a clear 501 when hosted container is served responses protocol 1.0.0
A 2.0.0-only hosted image served container protocol 1.0.0 (no x-agent-foundry-call-id
header) previously threw and surfaced an opaque 500 on every request. It now returns a
clear 501 "unsupported_container_protocol_version" naming the required protocol.
* HostedProtocolCompatibility gate keyed on FoundryEnvironment.IsHosted plus
PlatformContext.CallId (the 2.0.0 exclusive marker); invoked before isolation resolution
* HostedProtocolCompatibilityTests unit coverage; AgentFrameworkResponseHandlerTests note
clarifies the non-hosted path
* UnsupportedProtocolHostedAgentTests integration test deploys a dedicated
it-unsupported-protocol agent as 1.0.0 and asserts the 501 (validated live on cace)
* TestContainer recognizes the unsupported-protocol scenario
* it-bootstrap-agents.ps1 placeholder default raised to responses 2.0.0 and adds the
it-unsupported-protocol agent; HostedAgentFixture protocol version is overridable
* Address PR review: whitespace protocol gate and InMemory store agent keying
* HostedProtocolCompatibility treats a whitespace-only x-agent-foundry-call-id as
absent (IsNullOrWhiteSpace) so a proxy injecting whitespace cannot bypass the gate;
unit test covers empty, spaces and tab
* InMemoryAgentSessionStore keys sessions by agent.Name (omitting the agent segment
when Name is unset), mirroring FileSystemAgentSessionStore, so session continuity
survives a recreated or transient agent rather than keying on the per-instance agent.Id
Roger Barreto
f9b2fbb676