chore(openspec): archive cloud-planner-proxy

Change is complete (20/20 tasks). Deltas synced: MODIFIED the
agent-runtime "Pluggable dual-provider tool-calling abstraction"
requirement (added transport selection), and created a new main spec
openspec/specs/cloud-planner-proxy/spec.md.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

openspec/specs/cloud-planner-proxy/spec.md

@@ -0,0 +1,67 @@
+# cloud-planner-proxy Specification
+
+## Purpose
+Define the Cloud Control Plane's planner-decision proxy endpoint, which
+allows a Host Agent to delegate AI Planner LLM calls to the cloud using
+cloud-held provider credentials, removing the need for Host Agent-held
+provider API keys.
+
+## Requirements
+
+### Requirement: Cloud Control Plane exposes an authenticated planner-decision endpoint
+The Cloud Control Plane SHALL expose an internal endpoint that accepts an AI Planner tool-calling decision request from an authenticated Host Agent, and SHALL require the same host-scoped bearer credential already used for heartbeat, claim, lease renewal, and result reporting -- no separate credential or enrollment step.
+
+#### Scenario: Authenticated host requests a planner decision
+- **WHEN** a Host Agent presents its existing valid host-scoped credentials
+  with a planner-decision request
+- **THEN** the Cloud Control Plane accepts and processes the request for
+  that host
+
+#### Scenario: Unauthenticated or foreign-host request is rejected
+- **WHEN** a request omits valid host-scoped credentials, or presents
+  credentials bound to a different host than the one referenced in the
+  request
+- **THEN** the Cloud Control Plane rejects the request without invoking any
+  LLM provider
+
+### Requirement: Endpoint resolves exactly one tool-call decision using cloud-held provider configuration
+The Cloud Control Plane SHALL use its own configured LLM provider, model, and credentials -- not any value supplied by the requesting Host Agent -- to resolve a planner-decision request to exactly one tool name and one arguments object, within the request's timeout.
+
+#### Scenario: Provider returns a usable decision
+- **WHEN** the configured provider responds to a planner-decision request
+  with a tool call
+- **THEN** the Cloud Control Plane returns exactly one resolved tool name
+  and arguments object to the requesting Host Agent
+
+#### Scenario: Configured provider is unreachable or misconfigured
+- **WHEN** the Cloud Control Plane's configured provider call fails (for
+  example, invalid credentials, provider error, or timeout)
+- **THEN** the endpoint returns a structured failure response rather than a
+  fabricated decision, and does not crash the Cloud Control Plane process
+
+### Requirement: Cloud-proxy transport removes the need for Host Agent-held provider credentials
+A Host Agent using the cloud-proxy transport for its AI Planner SHALL be able to execute AI-planned tasks without any locally configured LLM provider API key.
+
+#### Scenario: Host configured for cloud-proxy transport has no local provider key
+- **WHEN** a Host Agent is configured to use the cloud-proxy transport and
+  has no `ANTHROPIC_API_KEY`/`OPENAI_API_KEY` set in its own environment
+- **THEN** it can still obtain AI Planner decisions by calling the Cloud
+  Control Plane's planner-decision endpoint
+
+### Requirement: Planner-decision requests are not durably persisted
+The Cloud Control Plane SHALL process planner-decision requests, including any screenshot and prompt text they carry, without durably persisting that screenshot or prompt content; only request metadata (such as host identifier, resolved tool name, latency, and error classification) may be retained for observability.
+
+#### Scenario: Request handling completes without storing prompt or screenshot content
+- **WHEN** the Cloud Control Plane finishes handling a planner-decision
+  request
+- **THEN** the raw prompt text and screenshot bytes from that request are
+  not present in any durable store or log the Cloud Control Plane retains
+
+### Requirement: Planner-proxy failures do not silently substitute a default action
+The Cloud Control Plane SHALL report a failure to the requesting Host Agent when it cannot resolve a planner-decision request to a valid tool call, rather than returning a default, guessed, or previously cached decision.
+
+#### Scenario: Endpoint cannot resolve a decision
+- **WHEN** the configured provider does not return a usable tool call for a
+  planner-decision request
+- **THEN** the Cloud Control Plane's response indicates failure, and the
+  requesting Host Agent treats the planner call for that turn as failed