Merge branch 'codex/simp-agent-entry-state' into codex/simp-unify-agent-session-id

# Conflicts:
#	docs/architecture.md
#	docs/config-catalog.md
#	docs/cordis-catalog/events.md
#	docs/cordis-catalog/services.md
#	docs/core-data-structures/core.md
#	docs/event-producer-consumer.md
#	docs/module-graph.md
#	examples/coding-agent/tests/code-mode.e2e.ts
#	examples/coding-agent/tests/coding-task.e2e.ts
#	examples/coding-agent/tests/compaction.e2e.ts
#	examples/coding-agent/tests/full-loop.e2e.ts
#	examples/coding-agent/tests/todo-write.e2e.ts
#	examples/cordis-agent/tests/cordis-tools.e2e.ts
#	packages/bash/tool-bash/tests/integration.spec.ts
#	packages/bash/tool-bash/tests/tools.spec.ts
#	packages/compact/compact-basic/tests/compact-loop-repro.spec.ts
#	packages/context/time-context/tests/time-context.spec.ts
#	packages/cordis/tool-cordis/src/api-catalog.ts
#	packages/cordis/tool-cordis/tests/integration.spec.ts
#	packages/core/agent-loop/README.md
#	packages/core/agent-loop/src/agent.ts
#	packages/core/agent-loop/src/index.ts
#	packages/core/agent-loop/tests/agent.spec.ts
#	packages/core/agent-loop/tests/cancel.spec.ts
#	packages/core/agent-loop/tests/config-session-id.spec.ts
#	packages/core/agent-loop/tests/contract-regressions.spec.ts
#	packages/core/agent-loop/tests/coverage-edges.spec.ts
#	packages/core/agent-loop/tests/interception.spec.ts
#	packages/core/agent-loop/tests/loop.spec.ts
#	packages/core/agent-loop/tests/properties.spec.ts
#	packages/core/agent-loop/tests/request-cache.e2e.ts
#	packages/core/agent-loop/tests/request-reconstruction.spec.ts
#	packages/core/agent-loop/tests/resume.spec.ts
#	packages/core/agent-loop/tests/scope-lifecycle.spec.ts
#	packages/core/agent-loop/tests/tool-order.spec.ts
#	packages/core/agent-loop/tests/turn-stop.spec.ts
#	packages/core/agent/src/types.ts
#	packages/examples/agent-spine-demo/README.md
#	packages/examples/agent-spine-demo/tests/agent-core.spec.ts
#	packages/examples/stdio-demo/README.md
#	packages/examples/stdio-demo/src/index.ts
#	packages/examples/stdio-demo/tests/stdio-agent.spec.ts
#	packages/fs/tool-fs/tests/fs-tools.e2e.ts
#	packages/guard/repeat-tool-guard/tests/repeat-tool-guard.spec.ts
#	packages/hooks/hooks-claude/tests/bridge.spec.ts
#	packages/hooks/hooks-claude/tests/coverage.spec.ts
#	packages/hooks/hooks-codex/tests/bridge.spec.ts
#	packages/hooks/hooks-codex/tests/coverage.spec.ts
#	packages/subagent/subagent-fork/tests/multi-subagent.spec.ts
#	packages/subagent/subagent-fork/tests/subagent-fork.spec.ts
#	packages/subagent/subagent-inprocess/tests/structured.spec.ts
#	packages/subagent/subagent-inprocess/tests/subagent-inprocess.spec.ts
#	packages/subagent/subagent-spawn/tests/spawn.e2e.ts
#	packages/subagent/subagent-spawn/tests/subagent-spawn.spec.ts
#	packages/todo/tool-todo/tests/integration.spec.ts
#	packages/ui/acp/tests/dispose.spec.ts
#	packages/ui/acp/tests/edges.spec.ts
#	packages/workflow/workflow-workerthread/tests/integration.spec.ts

packages/workflow/workflow-workerthread/src/runtime.ts

@@ -36,7 +36,7 @@ export interface ExecutionObserver {
 }
 
 /** The `agent()` options the script may pass; everything else rejects loud. */
-const SUPPORTED_AGENT_OPTIONS = new Set(['label', 'phase', 'schema', 'model'])
+const SUPPORTED_AGENT_OPTIONS = new Set(['label', 'phase', 'schema', 'provider', 'model'])
 /** Deferred Claude Code options we name explicitly in the rejection message. */
 const DEFERRED_AGENT_OPTIONS = new Set(['effort', 'isolation', 'agentType'])
 
@@ -277,6 +277,7 @@ export class WorkflowExecution {
         run = await this.children.startAgent({
           prompt: rawPrompt,
           ...opts.schema !== undefined ? { schema: opts.schema } : {},
+          ...opts.provider !== undefined ? { provider: opts.provider } : {},
           ...opts.model !== undefined ? { model: opts.model } : {},
         })
       } catch (error: unknown) {
@@ -344,7 +345,13 @@ export class WorkflowExecution {
   }
 
   /** Materialize + validate the `agent()` options bag from the realm. */
-  private readAgentOptions(rawOpts: unknown): { label?: string; phase?: string; model?: string; schema?: StructuredOutputSchema } {
+  private readAgentOptions(rawOpts: unknown): {
+    label?: string
+    phase?: string
+    provider?: string
+    model?: string
+    schema?: StructuredOutputSchema
+  } {
     if (rawOpts === undefined) return {}
     let opts: unknown
     try {
@@ -361,11 +368,11 @@ export class WorkflowExecution {
     for (const key of Object.keys(record)) {
       if (SUPPORTED_AGENT_OPTIONS.has(key)) continue
       if (DEFERRED_AGENT_OPTIONS.has(key)) {
-        throw new WorkflowError(`agent() option "${key}" is deferred and not supported by this engine (supported: label, phase, schema, model)`, 'UNSUPPORTED_OPTION')
+        throw new WorkflowError(`agent() option "${key}" is deferred and not supported by this engine (supported: label, phase, schema, provider, model)`, 'UNSUPPORTED_OPTION')
       }
-      throw new WorkflowError(`agent() option "${key}" is not recognized (supported: label, phase, schema, model)`, 'UNSUPPORTED_OPTION')
+      throw new WorkflowError(`agent() option "${key}" is not recognized (supported: label, phase, schema, provider, model)`, 'UNSUPPORTED_OPTION')
     }
-    for (const key of ['label', 'phase', 'model'] as const) {
+    for (const key of ['label', 'phase', 'provider', 'model'] as const) {
       if (record[key] !== undefined && typeof record[key] !== 'string') {
         throw new WorkflowError(`agent() option "${key}" must be a string`, 'INVALID_ARGUMENT')
       }
@@ -384,6 +391,7 @@ export class WorkflowExecution {
     return {
       ...record.label !== undefined ? { label: record.label as string } : {},
       ...record.phase !== undefined ? { phase: record.phase as string } : {},
+      ...record.provider !== undefined ? { provider: record.provider as string } : {},
       ...record.model !== undefined ? { model: record.model as string } : {},
       ...schema !== undefined ? { schema } : {},
     }