feat(settings): move config/state to owner buckets

Add generic /api/storage config/state endpoints with merge-patch, migrate legacy YAML/JSON layout, and update UI/server to read and write owner-scoped settings. Replace config SSE events and drop /api/config routes.

packages/server/src/settings/service.ts

@@ -0,0 +1,55 @@
+import type { Logger } from "../logger"
+import type { EventBus } from "../events/bus"
+import type { ConfigLocation } from "../config/location"
+import { YamlDocStore, type SettingsDoc } from "./yaml-doc-store"
+import { migrateSettingsLayout } from "./migrate"
+import type { WorkspaceEventPayload } from "../api-types"
+
+export type DocKind = "config" | "state"
+
+export class SettingsService {
+  private readonly configStore: YamlDocStore
+  private readonly stateStore: YamlDocStore
+
+  constructor(
+    private readonly location: ConfigLocation,
+    private readonly eventBus: EventBus | undefined,
+    private readonly logger: Logger,
+  ) {
+    migrateSettingsLayout(location, logger)
+    this.configStore = new YamlDocStore(location.configYamlPath, logger.child({ component: "settings-config" }))
+    this.stateStore = new YamlDocStore(location.stateYamlPath, logger.child({ component: "settings-state" }))
+  }
+
+  getDoc(kind: DocKind): SettingsDoc {
+    return kind === "config" ? this.configStore.get() : this.stateStore.get()
+  }
+
+  mergePatchDoc(kind: DocKind, patch: unknown): SettingsDoc {
+    const updated = kind === "config" ? this.configStore.mergePatch(patch) : this.stateStore.mergePatch(patch)
+    this.publish(kind, "*")
+    return updated
+  }
+
+  getOwner(kind: DocKind, owner: string): SettingsDoc {
+    return kind === "config" ? this.configStore.getOwner(owner) : this.stateStore.getOwner(owner)
+  }
+
+  mergePatchOwner(kind: DocKind, owner: string, patch: unknown): SettingsDoc {
+    const updated =
+      kind === "config" ? this.configStore.mergePatchOwner(owner, patch) : this.stateStore.mergePatchOwner(owner, patch)
+    this.publish(kind, owner, updated)
+    return updated
+  }
+
+  private publish(kind: DocKind, owner: string, value?: SettingsDoc) {
+    if (!this.eventBus) return
+    const type = kind === "config" ? "storage.configChanged" : "storage.stateChanged"
+    const payload: WorkspaceEventPayload = {
+      type,
+      owner,
+      value: value ?? this.getOwner(kind, owner),
+    } as any
+    this.eventBus.publish(payload)
+  }
+}