feat: unify installation model catalog

backend/src/routes/settings.ts

@@ -1,17 +1,27 @@
 import type { FastifyInstance } from "fastify";
 import type { AppConfig } from "../config.js";
 import type { Settings } from "../settings/settings-store.js";
-import { listWorkspaces, type ListModelsFn } from "./meta.js";
+import { listWorkspaces } from "./meta.js";
 import type { PrincipalContext } from "../auth/principal.js";
 import { isPrincipalContext, requirePermission } from "../auth/authorization.js";
+import {
+  splitCanonicalModelId,
+  type RuntimeModelCatalog,
+} from "../models/runtime-model-catalog.js";
 
-/** Merge stored settings over env/first-workspace defaults. */
-export function effectiveSettings(cfg: AppConfig, stored: Settings): Settings {
+/** Merge only workspace and runtime-thinking preferences; model defaults belong to modelCatalog. */
+export function effectiveSettings(
+  cfg: AppConfig,
+  stored: Settings,
+  modelCatalog?: RuntimeModelCatalog,
+): Settings {
   const workspaces = listWorkspaces(cfg.harnessDir);
+  const selected = modelCatalog?.defaultSession
+    ? splitCanonicalModelId(modelCatalog.defaultSession)
+    : undefined;
   return {
     workspace: stored.workspace ?? workspaces[0]?.name,
-    provider: cfg.defaults.provider ?? stored.provider,
-    model: cfg.defaults.model ?? stored.model,
+    ...(selected ?? {}),
     thinking: cfg.defaults.thinking ?? stored.thinking,
   };
 }
@@ -19,7 +29,7 @@ export function effectiveSettings(cfg: AppConfig, stored: Settings): Settings {
 export function settingsRoutes(
   app: FastifyInstance,
   deps: {
-    cfg: AppConfig; listModels: ListModelsFn;
+    cfg: AppConfig;
     getSettings: (principal: PrincipalContext) => Promise<Settings>;
   },
 ): void {
@@ -37,22 +47,6 @@ export function settingsRoutes(
     const principal = requirePermission(req, reply, "settings.manage");
     if (!isPrincipalContext(principal)) return principal;
     const b = (req.body ?? {}) as Settings;
-    if (b.model) {
-      let available: { provider: string; id: string }[] = [];
-      try {
-        available = await deps.listModels();
-      } catch {
-        available = [];
-      }
-      // Only validate when Pi gave us a non-empty list; otherwise allow (degraded).
-      if (available.length > 0 && !available.some(
-        (candidate) => candidate.provider === b.provider && candidate.id === b.model,
-      )) {
-        return reply.code(400).send({
-          error: `Unknown model: ${b.provider ?? "unknown"}/${b.model}`,
-        });
-      }
-    }
     try {
       // Retain this endpoint as a validating compatibility surface for older clients, but do
       // not write anonymous users' choices to shared server storage.