…d provisioning client

Resource model:
- RabbitMQVirtualHostResource: IResourceWithParent<RabbitMQServerResource>,
  IResourceWithConnectionString, vhost-aware AMQP URI, internal TopologyReady TCS,
  internal ApplyAsync(IRabbitMQProvisioningClient)
- RabbitMQQueueResource: IResourceWithParent<RabbitMQVirtualHostResource>,
  IRabbitMQDestination, Durable/Exclusive/AutoDelete/QueueType/Arguments
- RabbitMQExchangeResource: IRabbitMQDestination, Type/Durable/AutoDelete/Arguments,
  internal List<RabbitMQBinding>, ApplyAsync + ApplyBindingsAsync
- RabbitMQBinding: [AspireDto] POCO (Destination, RoutingKey, Arguments)
- RabbitMQShovelResource: IResourceWithParent<RabbitMQVirtualHostResource>,
  Source/Destination endpoints, AckMode, ReconnectDelay, SrcDeleteAfter
- RabbitMQShovelEndpoint: [AspireDto] wrapping IRabbitMQDestination

Provisioning client:
- IRabbitMQProvisioningClient: 9-method internal interface (AMQP + HTTP)
- RabbitMQProvisioningClient: sync ctor, lazy GetOrCreateChannelAsync /
  GetOrCreateHttpClientAsync, per-vhost IChannel cache, normalises errors
- RabbitMQShovelDefinition: internal JSON record for PUT /api/parameters/shovel
- RabbitMQTopologyProvisioner: pure orchestration — vhost → exchanges → queues
  → bindings → shovels → TopologyReady.TrySetResult()

…ge, Shovel, Plugin

New builder methods (all decorated with [AspireExport] or [AspireExportIgnore]):
- AddVirtualHost: auto-enables management plugin for non-'/' vhosts
- GetOrAddDefaultVirtualHost: lazy idempotent '/' vhost creation
- AddQueue (vhost + server overloads): creates RabbitMQQueueResource
- AddExchange (vhost + server overloads): creates RabbitMQExchangeResource
- WithProperties (queue/exchange/shovel): ATS-exported configure callbacks
- WithBinding<TDest>: same-vhost validation + WithRelationship
- AddShovel<TSrc,TDest> (vhost + server overloads): auto-enables shovel plugins
- WithPlugin(RabbitMQPlugin) + WithPlugin(string): lazy enabled_plugins file
  generation via WithContainerFiles; management defaults always included

DI wiring:
- Register IRabbitMQProvisioningClient as keyed singleton per server
- Subscribe ResourceReadyEvent → RabbitMQTopologyProvisioner (no-op when empty)
- Replace ad-hoc IConnection? closure with client reuse for server health check

Per-child health checks:
- Vhost: AMQP connect on vhost after TopologyReady
- Queue: QueueExistsAsync after TopologyReady
- Exchange: ExchangeExistsAsync after TopologyReady
- Shovel: GetShovelStateAsync == 'running' after TopologyReady

…ins, and public API

New test files:
- TestServices/FakeRabbitMQProvisioningClient: records all calls; shared by
  unit tests and provisioner ordering tests
- AddRabbitMQChildResourcesTests: parent/child wiring, idempotent default vhost,
  cross-vhost validation, connection-string expressions
- RabbitMQTopologyProvisionerTests: call ordering (vhost→exchanges→queues→
  bindings→shovels), TopologyReady completion, exception propagation
- RabbitMQPluginTests: enabled_plugins generation, dedup, management defaults
  always included, enum→string mapping, auto-enable matrix

Extended test files:
- ConnectionPropertiesTests: snapshot test extended with vhost/queue/exchange
  manifests (snapshot generated on first run)
- RabbitMQPublicApiTests: null/empty argument guards for all new builder methods
  (AddVirtualHost, AddQueue, AddExchange, WithProperties, WithBinding, WithPlugin)

…s; add design plan

README additions:
- Virtual host, queue, exchange, binding, shovel usage examples
- Server-level convenience overloads section
- WithProperties section
- Plugin customization section with auto-enable matrix table
- Connection properties table for VirtualHost, Queue, Exchange resources

plans/rabbitmq-child-resources.md: full approved design document covering
resource model, builder API, provisioning architecture, WaitFor semantics,
plugin file generation, validation rules, and implementation backlog

…namespace

Replace the single vhost-level TopologyReady TCS with per-resource
ProvisioningComplete TCSs so that partial provisioning failures are
attributed only to the affected resource, not to all siblings.

Changes:
- IRabbitMQProvisionable: add Name, ProvisioningComplete, HealthDependencies
  (default []), and ProbeAsync (default Healthy) so each resource owns its
  own health semantics without pulling HealthChecks into the model layer.
- RabbitMQProbeResult: new internal record struct keeping resource classes
  free of Microsoft.Extensions.Diagnostics.HealthChecks.
- IRabbitMQProvisioningClient / RabbitMQProvisioningClient: add CanConnectAsync
  used by the vhost probe, eliminating the concrete-type cast that existed
  in the old vhost health-check registration.
- RabbitMQVirtualHostResource: remove TopologyReady; add ProvisioningComplete;
  ProbeAsync -> CanConnectAsync.
- RabbitMQQueueResource: add ProvisioningComplete; ProbeAsync -> QueueExistsAsync;
  HealthDependencies stub (AppliedPolicies, populated by future policy feature).
- RabbitMQExchangeResource: same pattern; ProbeAsync -> ExchangeExistsAsync.
- RabbitMQShovelResource: add ProvisioningComplete; ProbeAsync -> GetShovelStateAsync.
- RabbitMQProvisionableHealthCheck: single IHealthCheck implementation shared
  by all child resources: await self TCS -> await each dep TCS -> ProbeAsync.
- RabbitMQTopologyProvisioner: rewritten with ApplyAndSignalAsync helper.
  Phase-1 vhost failure cascades to all children (only legitimate cascade).
  Phase-2/3 failures are captured per-entity without short-circuiting siblings.
  Exchange ProvisioningComplete fires after both declare AND bindings.
- RabbitMQBuilderExtensions: single private WithProvisionableHealthCheck<T>
  helper replaces four inline HealthCheckRegistration blocks; all Add* call
  sites become identical one-liners. File-scoped RabbitMQEntityHealthCheck
  deleted.
- Tests: FakeRabbitMQProvisioningClient gains CanConnectAsync and per-entity
  failure injection (FailQueueNames, FailExchangeNames, FailBindingSourceExchangeNames).
  FailingFakeRabbitMQProvisioningClient gains CanConnectAsync. Provisioner
  tests updated to use ProvisioningComplete and extended with isolation cases
  (queue-B fails, binding fails, vhost fails). New RabbitMQProvisionableHealthCheckTests
  covers all health-check stages and per-resource ProbeAsync.

docs/specs/rabbitmq-health-checks.md: contributor-facing design spec
covering the guiding principle, key design decisions (per-resource TCS,
two-stage check, resource-owned semantics, probe result type, binding/shovel/
policy attribution rules), and extension guidance for adding new resource types.

src/Aspire.Hosting.RabbitMQ/README.md: add 'Health checks' section with the
user-facing contract — failure isolation, the vhost cascade, and binding
attribution — without volatile implementation detail.

- RabbitMQPolicyApplyTo enum (Queues, Exchanges, All)
- RabbitMQPolicyResource: IResourceWithParent<RabbitMQVirtualHostResource>,
  IRabbitMQProvisionable; props PolicyName/Pattern/ApplyTo/Definition/Priority;
  internal AppliesTo(entityName, kind) with cached compiled Regex;
  default HealthDependencies=[]; default ProbeAsync=Healthy
- RabbitMQPolicyDefinition: internal JSON record for PUT /api/policies/{vhost}/{name}
- RabbitMQVirtualHostResource: add internal Policies list; cascade policy TCS
  faults in vhost-failure path
- RabbitMQQueueResource + RabbitMQExchangeResource: add AppliedPolicies list;
  explicit-impl HealthDependencies => AppliedPolicies
- IRabbitMQProvisioningClient + RabbitMQProvisioningClient: add PutPolicyAsync
- RabbitMQTopologyProvisioner: Phase 1.5 applies policies after vhost creation
  and before entity declaration; cascade policy TCS faults on vhost failure
- RabbitMQBuilderExtensions: AddPolicy (vhost + server overloads), WithProperties
  for policy; BeforeStartEvent handler resolves pattern matches lazily;
  internal ResolveAndApplyPolicyMatches helper for testability
- FakeRabbitMQProvisioningClient: add PutPolicyAsync stub + FailPolicyNames
- FailingFakeRabbitMQProvisioningClient: add PutPolicyAsync stub
- RabbitMQProvisionableHealthCheckTests: add PutPolicyAsync to FixedShovelStateClient
- RabbitMQPolicyTests: 20 tests covering wiring, lazy matching, provisioner
  ordering, health dependency isolation
- README: add Policies section

…esourceLoggerService logging, ProvisionedName rename, policy health check + probe, vhost existence check, cross-vhost shovels, enabled_plugins cleanup, Queue.Arguments docs

…tate

Replace the externally-signaled TaskCompletionSource on IRabbitMQProvisionable
with a read-only Task ProvisionedTask. Each resource now owns its TCS privately
and signals it from within ApplyAsync (and ApplyBindingsAsync for exchanges).

Resources also publish their own Aspire lifecycle state (Starting/Running/
FailedToStart) via ResourceNotificationService passed into ApplyAsync, so
child resources appear in the dashboard resource list with correct state.

Key changes:
- IRabbitMQProvisionable: TaskCompletionSource ProvisioningComplete ->
  Task ProvisionedTask; ApplyAsync gains ResourceNotificationService and
  ResourceLoggerService parameters; implementations must not throw
- All five resource classes: TCS is private readonly; ApplyAsync publishes
  Starting -> Running/FailedToStart and signals TCS internally
- RabbitMQExchangeResource: ApplyAsync publishes Running after declaration
  (exchange is live); ApplyBindingsAsync signals TCS after bindings
- RabbitMQTopologyProvisioner: no TCS manipulation anywhere; cascade-fault
  block deleted (children stay Degraded/Starting when vhost fails);
  provisioner collapses to a single ProvisionVirtualHostAsync method
- RabbitMQProvisionableHealthCheck: ProvisioningComplete.Task ->
  ProvisionedTask (two property references)
- docs/specs/rabbitmq-health-checks.md: updated with two-signal model,
  lifecycle/health state matrix, and updated extension guidance