Only memory comes from the server's /mcp; notes, knowledge and skills stay local

Harness spec 3.0.0 (acp.md *Memory*): memory records are the server's for the
device as for a chat; everything else in the library is the device's own.

- `library: lembas` (the default when the login's token has the `memory`
  scope, or the older `library`) adds the server's /mcp with its `memory`
  tool alone, in place of this machine's memory tool; notes_*, knowledge_*
  and skill_* are always this machine's. No prompts, resources or
  instructions are taken from it.
- The memory in the prompt is the server's: the resource lembas://memory,
  read as a session starts (McpManager.readResource) and kept for it — put in
  while nothing has been sent, so the prompt never changes under a session.
- A session the client opened (session/new, or opened from the store) sends
  its id as `_meta.lembas.scope` on every memory call and on the resource
  read (App.setScope); a session of the device's own sends none.
- An instance's `library` context (its knowledge bases) is no longer read:
  the knowledge block names this machine's bases only.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/harness.test.ts

@@ -220,7 +220,7 @@ test("every {{variable}} in a description is declared, and none reaches a model"
       else expect(system).not.toContain("The current plan")
     }
   }
-  app.setContext({ instructions: "Be brief.", prototypes: { offered: true, sources: "" }, library: { bases: [{ id: "k", name: "K" }] } }, "example")
+  app.setContext({ instructions: "Be brief.", prototypes: { offered: true, sources: "" } }, "example")
   const withContext = app.engine.o.system("manual", app.engine.model, plan)
   expect(withContext).not.toContain("{{")
   expect(withContext).toContain("## Instructions from example\n\nBe brief.")