Settings: server-side LLM configurations + 30d spend roll-up

Replaces the localStorage-only LLM settings with a persisted catalogue
backed by /api/v1/admin/llm-configurations. The Settings → LLM screen
now has two cards:

- "Saved configurations" — full CRUD against the server. Each row shows
  provider/model/secret/published per-1M-token costs. Add wizard
  auto-fills costs from the curated catalog. One-click "Import local"
  button promotes any pre-existing localStorage settings into a server
  row, then clears the local store.
- "Active LLM (this session)" — the existing LLMProvidersSettingsCard,
  scoped down to "what does the Assistant use right now" (still
  localStorage; per-operator).

Spend (30d) tile in the configurations card header reads
/api/v1/ai/llm/usage/summary and surfaces total cost / requests /
tokens. First visible cost roll-up in the admin UI.

New module app/lib/arcadia/llm-configs.ts: typed CRUD client,
catalog lookup, computeCostCents helper (mirrors the server's
LlmConfiguration.compute_cost_cents/3), and getUsageSummary.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

app/lib/arcadia/llm-configs.ts

@@ -0,0 +1,155 @@
+// Arcadia LLM configurations API.
+//
+// Backed by /api/v1/admin/llm-configurations — server-side persisted
+// provider/model/secret/cost settings. Replaces the localStorage-driven
+// settings the admin UI used previously, so configurations and costs
+// survive across browsers and operators.
+//
+// `tenant_id: null` configurations are platform-defaults visible to
+// every tenant. Names are unique within (tenant, name).
+
+import type { ArcadiaClient } from "@crema/arcadia-client"
+
+export type LlmProvider = "openai" | "anthropic" | "deepseek" | "qwen" | "lmstudio"
+
+export interface LlmConfiguration {
+  id: string
+  tenant_id: string | null
+  name: string
+  provider: LlmProvider
+  model: string
+  base_url: string | null
+  secret_name: string | null
+  input_cost_per_million: number | null
+  output_cost_per_million: number | null
+  enabled: boolean
+  metadata: Record<string, unknown>
+  inserted_at: string
+  updated_at: string
+}
+
+export interface LlmConfigurationInput {
+  tenant_id?: string | null
+  name: string
+  provider: LlmProvider
+  model: string
+  base_url?: string | null
+  secret_name?: string | null
+  /** USD per 1M tokens. Omit to auto-fill from the catalog. */
+  input_cost_per_million?: number | null
+  output_cost_per_million?: number | null
+  enabled?: boolean
+  metadata?: Record<string, unknown>
+}
+
+export interface CatalogEntry {
+  provider: LlmProvider
+  model: string
+  input_cost_per_million: number
+  output_cost_per_million: number
+  context_window: number | null
+  notes: string | null
+}
+
+const BASE = "/api/v1/admin/llm-configurations"
+
+export async function listConfigurations(
+  arcadia: ArcadiaClient,
+  opts: { enabled?: boolean; tenant_id?: string } = {},
+): Promise<LlmConfiguration[]> {
+  const params: Record<string, string | number | boolean | null | undefined> = {}
+  if (opts.enabled != null) params.enabled = String(opts.enabled)
+  if (opts.tenant_id) params.tenant_id = opts.tenant_id
+  const res = await arcadia.GET<{ data: LlmConfiguration[] }>(BASE, { params })
+  return res.data
+}
+
+export async function getConfiguration(
+  arcadia: ArcadiaClient,
+  id: string,
+): Promise<LlmConfiguration> {
+  const res = await arcadia.GET<{ data: LlmConfiguration }>(`${BASE}/${id}`)
+  return res.data
+}
+
+export async function createConfiguration(
+  arcadia: ArcadiaClient,
+  input: LlmConfigurationInput,
+): Promise<LlmConfiguration> {
+  const res = await arcadia.POST<{ data: LlmConfiguration }>(BASE, {
+    body: { configuration: input },
+  })
+  return res.data
+}
+
+export async function updateConfiguration(
+  arcadia: ArcadiaClient,
+  id: string,
+  input: Partial<LlmConfigurationInput>,
+): Promise<LlmConfiguration> {
+  const res = await arcadia.PATCH<{ data: LlmConfiguration }>(`${BASE}/${id}`, {
+    body: { configuration: input },
+  })
+  return res.data
+}
+
+export async function deleteConfiguration(
+  arcadia: ArcadiaClient,
+  id: string,
+): Promise<void> {
+  await arcadia.DELETE(`${BASE}/${id}`)
+}
+
+export async function getCatalog(arcadia: ArcadiaClient): Promise<CatalogEntry[]> {
+  const res = await arcadia.GET<{ data: CatalogEntry[] }>(`${BASE}/catalog`)
+  return res.data
+}
+
+/**
+ * Compute cost in cents for a given input/output token count using a
+ * configuration's published rates. Mirrors `LlmConfiguration.compute_cost_cents/3`
+ * in arcadia-app — keep in sync.
+ */
+export function computeCostCents(
+  config: Pick<LlmConfiguration, "input_cost_per_million" | "output_cost_per_million">,
+  inputTokens: number,
+  outputTokens: number,
+): number {
+  const inRate = config.input_cost_per_million ?? 0
+  const outRate = config.output_cost_per_million ?? 0
+  const cents = ((inputTokens * inRate + outputTokens * outRate) / 1_000_000) * 100
+  return Math.round(cents)
+}
+
+/** Format a cost in cents as "$X.XX" or "$0.0XX" for sub-dollar amounts. */
+export function formatCost(cents: number): string {
+  if (cents === 0) return "$0"
+  if (cents < 100) return `$${(cents / 100).toFixed(2)}`
+  return `$${(cents / 100).toLocaleString(undefined, { minimumFractionDigits: 2, maximumFractionDigits: 2 })}`
+}
+
+// ---------------------------------------------------------------------------
+// LLM usage summary (cost roll-up)
+// ---------------------------------------------------------------------------
+
+export interface LlmUsageSummary {
+  total_requests: number | null
+  total_input_tokens: number | null
+  total_output_tokens: number | null
+  total_tokens: number | null
+  total_cost_cents: number | null
+  avg_latency_ms: number | null
+}
+
+export async function getUsageSummary(
+  arcadia: ArcadiaClient,
+  opts: { days?: number } = {},
+): Promise<LlmUsageSummary> {
+  const params: Record<string, string | number | boolean | null | undefined> = {}
+  if (opts.days != null) params.days = opts.days
+  const res = await arcadia.GET<{ data: LlmUsageSummary } | LlmUsageSummary>(
+    "/api/v1/ai/llm/usage/summary",
+    { params },
+  )
+  return "data" in (res as object) ? (res as { data: LlmUsageSummary }).data : (res as LlmUsageSummary)
+}