AgentServer: integrate resilient tasks with memory snapshot session activation

sdk/agentserver/azure-ai-agentserver-core/CHANGELOG.md

@@ -8,6 +8,20 @@
 
 ### Bugs Fixed
 
+- Preserve environment and configuration rollback snapshots across failed
+  restore cleanup retries so sparse overrides retain the captured baseline.
+- Retry interrupted restore rollback cleanup before activating a replacement
+  TaskManager, retaining queued-input reconciliation handles across transient
+  storage failures.
+- Reset task startup admission when reusing a host across sequential lifespans.
+- Reconcile interrupted steering transitions before restore rollback completes,
+  retaining queued work as recoverable without dispatching a new turn.
+- Preserve unfinished task records and saved inputs when failed restore
+  activation stops workers before rolling back session configuration.
+- Keep the lease instance stable on same-restore retries, retain worker and
+  lease handles until workers finish, and defer steering execution during
+  rollback while keeping queued input eligible for recovery.
+
 ### Other Changes
 
 ## 2.3.0b1 (2026-10-15)
@@ -30,6 +44,13 @@
   the restored session through the ambient request context during callbacks.
   Environment-backed `AgentConfig` values are refreshed in place before
   callbacks run, and `AgentSessionContext` is marked experimental.
+- Separate process-side task registration from session-bound task activation.
+  `FOUNDRY_MEMORY_SNAPSHOT_ENABLED=true` defers enabled tasks during capture until
+  after-restore; absent or false keeps ordinary cold startup. Resilience opt-out
+  remains disabled for both initialization paths. Preserve
+  best-effort recovery, checkpoint initialization phases by restore ID, wait for
+  owned workers to stop before incompatible configuration rollback, and stop
+  managers created after startup at shutdown.
 
 ### Bugs Fixed
 

sdk/agentserver/azure-ai-agentserver-core/README.md

@@ -2,6 +2,30 @@
 
 The `azure-ai-agentserver-core` package provides the foundation host framework for building Azure AI Hosted Agent containers. It handles the protocol-agnostic infrastructure — health probes, graceful shutdown, OpenTelemetry tracing, and ASGI serving — so that protocol packages can focus on their endpoint logic.
 
+## Memory snapshot task initialization
+
+The draft integration separates task definitions from session-bound TaskManager
+initialization. Resilient tasks must still be explicitly enabled.
+
+`FOUNDRY_MEMORY_SNAPSHOT_ENABLED=true` defers enabled tasks in the temporary
+capture sandbox until the platform after-restore hook, after session hydration
+and dependency callbacks. An absent value or `false` activates enabled tasks
+during ordinary cold/local startup. `set_resilient_tasks_enabled(False)` keeps
+the subsystem disabled at startup and after-restore regardless of this variable.
+Present values must be literal `true` or `false` (case-insensitive). The variable
+does not gate running tasks or lease renewal after activation.
+
+Task startup checkpoints completed phases by restore ID and owns the manager
+through shutdown, including managers created after lifespan startup. Existing
+best-effort recovery dispatches reclaimed work immediately during the hook.
+FHA admits new requests after successful restore.
+
+Author startup task submissions are not queued or replayed by this integration.
+No session-start callback or launch-intent registry is included. Local tests are
+not proof of hosted golden restoration. See the [design specification](https://github.com/Azure/azure-sdk-for-python/blob/main/sdk/agentserver/azure-ai-agentserver-core/docs/memory-snapshot-task-integration.md)
+for lifecycle ordering, launcher compatibility requirements, validation, and
+the unresolved startup-submission options.
+
 ## Getting started
 
 ### Install the package

sdk/agentserver/azure-ai-agentserver-core/azure/ai/agentserver/core/_lifecycle.py

@@ -7,10 +7,13 @@
 from collections.abc import Mapping
 from dataclasses import dataclass, field
 from types import MappingProxyType
-from typing import Awaitable, Callable, Optional
+from typing import TYPE_CHECKING, Awaitable, Callable, Optional
 
 from ._experimental import experimental
 
+if TYPE_CHECKING:
+    from .tasks._manager import TaskManager
+
 
 @experimental
 @dataclass(frozen=True, init=False)
@@ -45,6 +48,13 @@ def __init__(
         )
 
 
+@dataclass
+class _LifecycleRollback:
+    environment: dict[str, object] = field(repr=False)
+    config: dict[str, object] = field(repr=False)
+    task_manager: Optional["TaskManager"]
+
+
 @dataclass
 class _LifecycleState:
     lock: asyncio.Lock = field(default_factory=asyncio.Lock)
@@ -56,3 +66,4 @@ class _LifecycleState:
     completed_restore_ids: set[str] = field(default_factory=set)
     captured_environment_values: dict[str, Optional[str]] = field(default_factory=dict)
     applied_environment_variables: set[str] = field(default_factory=set)
+    pending_rollback: Optional[_LifecycleRollback] = None