feat(pi): fetch and refresh upstream model lists, searchable model picker

- POST /pi/upstreams/{id}/models/refresh calls the provider's model list
  endpoint (OpenAI-shaped /models, Anthropic /v1/models, Google
  /v1beta/models, OpenRouter /api/v1/models; Radius via pi-ai refresh),
  normalizes {id, displayName, contextWindow, supportsVision,
  supportsTools, pricing} and stores it in pi_upstream.models (0044)
- GET .../models returns {source, fetchedAt, models[]}: remote merged
  with the static catalog (remote first); failures (401/network/
  unsupported) fall back to static with a one-line error
- POST /pi/models/probe for trying credentials before creating
- wizard and edit drawer: fetch button, searchable dropdown with
  vision/tool tags, manual id, source line; default upstream needs a model
- tests: mock /models, 401, network failure; smoke step; runbook

Co-Authored-By: Claude Opus 5.5 <[email protected]>

apps/server/src/modules/pi/routes.ts

@@ -5,6 +5,7 @@ import {
   Api,
   apiResponse,
   type EndpointDef,
+  type PiModelsProbeRequest,
   type PiOAuthCompleteRequest,
   type PiOAuthStartRequest,
   type PiUpstreamCreate,
@@ -13,8 +14,8 @@ import {
 } from "@umt/contracts";
 import type { z } from "zod";
 import { requireAdminSession, requireScope } from "../../http/auth.ts";
-import { ApiException } from "../../http/errors.ts";
 import type { ModuleApp, ServerContext } from "../types.ts";
+import { probeModels, readUpstreamModels, refreshUpstreamModels } from "./models.ts";
 import type { OAuthSessions } from "./oauth.ts";
 import { requireRow } from "./oauth.ts";
 import { refreshUpstream, resolveExpiredDecision } from "./refresh.ts";
@@ -125,16 +126,21 @@ export function registerPiRoutes(
     return { ...out, mode, latencyMs: Date.now() - started, upstream: await toView(ctx, (await getRow(ctx, row.id))!) };
   });
 
-  route(app, Api.pi.models, async ({ params }) => {
+  route(app, Api.pi.models, async ({ params }) => await readUpstreamModels(ctx, await requireRow(ctx, params.id)));
+
+  route(app, Api.pi.modelsRefresh, async ({ params, actor }) => {
     const row = await requireRow(ctx, params.id);
-    try {
-      return await clientFor(ctx, row, deps.client).listModels();
-    } catch (err) {
-      if (err instanceof UpstreamError) throw new ApiException("validation_failed", err.message);
-      throw err;
-    }
+    const r = await refreshUpstreamModels(ctx, row);
+    await auditPi(ctx, actor, "pi_upstream.models_refresh", row.id, {
+      source: r.source,
+      count: r.models.length,
+      errorKind: r.errorKind,
+    });
+    return r;
   });
 
+  route(app, Api.pi.modelsProbe, async ({ body }) => await probeModels(body as PiModelsProbeRequest));
+
   route(app, Api.pi.oauthStart, async ({ params, body, actor }) => {
     const row = await requireRow(ctx, params.id);
     const r = await deps.oauth().start(row, body as PiOAuthStartRequest);