fix(headless): dsh run is a direct core front door

packages/core/agent-default-model/src/index.ts

@@ -0,0 +1,107 @@
+/**
+ * Default model selection for an Agent without a session-specific selection.
+ *
+ * @module @deepseek-ai/dsh-agent-default-model
+ */
+
+import { Context, Service } from 'cordis'
+import z from 'schemastery'
+import type { ModelSelection } from '@deepseek-ai/dsh-agent'
+import { ReasoningEffortId } from '@deepseek-ai/dsh-llm'
+import { installSettingsSection, settingsNamespace } from '@deepseek-ai/dsh-settings'
+
+declare module 'cordis' {
+  interface Context {
+    /** Default model selection for Agents created without an explicit model. */
+    agentDefaultModel: AgentDefaultModelService
+  }
+}
+
+/** Settings namespace carrying the default model selection for future Agents. */
+export const AGENT_DEFAULT_MODEL_SETTINGS_NAMESPACE = settingsNamespace('agent-default-model')
+
+/** Stored and composed default model selection. */
+export interface AgentDefaultModelSettings {
+  /** Registered provider route. */
+  provider: string
+  /** Provider-owned model id. */
+  model: string
+  /** Adapter-owned reasoning effort, or provider/default behavior when absent. */
+  reasoningEffort?: string
+}
+
+/** Schema of the default Agent model settings section. */
+export const AGENT_DEFAULT_MODEL_SETTINGS_SCHEMA: z<AgentDefaultModelSettings> = z.object({
+  provider: z.string().required(),
+  model: z.string().required(),
+  reasoningEffort: z.string(),
+})
+
+/** Composition entry for the default model selection. */
+export interface Config {
+  /** Registered provider route. */
+  provider: string
+  /** Provider-owned model id. */
+  model: string
+}
+
+/** Project stored settings onto the Agent-facing selection type. */
+function selection(settings: AgentDefaultModelSettings): ModelSelection {
+  return {
+    provider: settings.provider,
+    model: settings.model,
+    ...settings.reasoningEffort === undefined
+      ? {}
+      : { reasoningEffort: ReasoningEffortId(settings.reasoningEffort) },
+  }
+}
+
+/**
+ * Owns the default model selection independently of any Host or transport.
+ * The composition entry remains usable without a settings provider; when one
+ * is mounted, its user layer is read live.
+ */
+export class AgentDefaultModelService extends Service {
+  static Config: z<Config> = z.object({
+    provider: z.string().required(),
+    model: z.string().required(),
+  })
+
+  private source: () => AgentDefaultModelSettings
+
+  constructor(ctx: Context, config: Config) {
+    super(ctx, 'agentDefaultModel')
+    const entry: AgentDefaultModelSettings = { provider: config.provider, model: config.model }
+    this.source = () => entry
+    installSettingsSection(ctx, AGENT_DEFAULT_MODEL_SETTINGS_NAMESPACE, AGENT_DEFAULT_MODEL_SETTINGS_SCHEMA, entry, {
+      setSource: (current) => { this.source = current },
+      // Every consumer reads through currentSelection(), so no registration-level fact
+      // needs rebuilding when the settings document changes.
+      onChange: () => {},
+    })
+  }
+
+  /**
+   * Read the current default model selection.
+   * @returns a detached provider, model, and optional reasoning selection.
+   */
+  currentSelection(): ModelSelection {
+    return selection(this.source())
+  }
+
+  /**
+   * Save the complete default model selection. A deployment without a settings
+   * provider keeps its composition entry.
+   * @param next - resolved selection accepted by a front door.
+   * @returns fulfillment after the optional settings write settles.
+   */
+  async saveSelection(next: ModelSelection): Promise<void> {
+    await this.ctx.get('settings')?.replace(AGENT_DEFAULT_MODEL_SETTINGS_NAMESPACE, {
+      provider: next.provider,
+      model: next.model,
+      ...next.reasoningEffort === undefined ? {} : { reasoningEffort: String(next.reasoningEffort) },
+    })
+  }
+}
+
+export default AgentDefaultModelService

packages/core/agent-default-model/src/invariant.ts

@@ -0,0 +1,30 @@
+/**
+ * Package-owned invariant companion for the default Agent model selection.
+ *
+ * The service owns no independent event relationship: settings registration
+ * already validates every mutable value before `currentSelection()` can observe it.
+ * The empty installer keeps that absence explicit in composed invariant sets.
+ *
+ * @module @deepseek-ai/dsh-agent-default-model/invariant
+ */
+
+import type { Context } from 'cordis'
+import type { InvariantInstaller } from '@deepseek-ai/dsh-invariants'
+
+const PACKAGE_NAME = '@deepseek-ai/dsh-agent-default-model'
+
+/** Cordis companion plugin name. */
+export const name = 'agent-default-model-invariant'
+/** Services required before the companion can register. */
+export const inject = ['invariants']
+
+/** No runtime invariant: settings validation owns the only mutable-value relationship. */
+const install: InvariantInstaller = () => {}
+
+/**
+ * Register the intentionally empty invariant contribution.
+ * @param ctx - Cordis context carrying the invariant service.
+ * @returns the installed registration's disposer after setup succeeds.
+ */
+export const apply = (ctx: Context): Promise<() => void> =>
+  Promise.resolve(ctx.invariants.register(PACKAGE_NAME, install))