fix(core): default custom agents to primary (#40880)

Co-authored-by: Aiden Cline <rekram1-node@users.noreply.github.com>

packages/core/test/agent.test.ts

@@ -126,6 +126,7 @@ describe("Agent", () => {
 
       yield* agent.transform((editor) => editor.update(id, () => {}))
       const info = yield* agent.get(id)
+      expect(info?.mode).toBe("primary")
       expect(info?.permissions.slice(0, Agent.Info.default(id).permissions.length)).toEqual(
         Agent.Info.default(id).permissions,
       )

packages/schema/src/agent.ts

@@ -41,7 +41,7 @@ export const Info = Schema.Struct({
           id,
           name: Name.make(id),
           request: { settings: {}, headers: {}, body: {} },
-          mode: "all",
+          mode: "primary",
           hidden: false,
           permissions: [
             { action: "*", resource: "*", effect: "allow" },

packages/www/content/docs/(Configure)/agents.mdx

@@ -46,9 +46,9 @@ An agent's `mode` controls where it can run:
 
 | Mode | Behavior |
 | --- | --- |
-| `primary` | Can be selected as the main agent for a session. It cannot be launched as a subagent. |
+| `primary` | Can be selected as the main agent for a session. It cannot be launched as a subagent. This is the default for a custom agent when `mode` is omitted. |
 | `subagent` | Can run in a child session through the `subagent` tool, but cannot be selected as the main agent. |
-| `all` | Can be used either way. This is the default for a custom agent when `mode` is omitted. |
+| `all` | Can be used either way. |
 
 In the TUI, press <kbd>Tab</kbd> and <kbd>Shift</kbd>+<kbd>Tab</kbd> to cycle
 through visible primary and `all` agents, or use `/agents` to choose one.