fix(desktop): fold baked build env into in-process model discovery (#1376)

Signed-off-by: Will Pfleger <pfleger.will@gmail.com>
Co-authored-by: npub1mn7jgtj4w2pd0g0zeuhxsa6jy6p0rewxz4kujt98my82ahfmp72sxjexk7 <dcfd242e557282d7a1e2cf2e6877522682f1e5c6156dc92ca7d90eaedd3b0f95@sprout-oss.stage.blox.sqprod.co>

desktop/src/shared/api/types.ts

@@ -574,6 +574,7 @@ export type UpdateManagedAgentInput = {
   pubkey: string;
   name?: string;
   model?: string | null;
+  provider?: string | null;
   systemPrompt?: string | null;
   mcpToolsets?: string | null;
   /** Absent = don't touch. Present = replace the env_vars map entirely. */