Subagents in the CLI (harness spec 3.3.0): the model, capacity, the offer, /context

- A task subagent or a team member runs on the session's model unless the
  person named another in this session's own messages (team/subagents.ts;
  engine.personSaid reads every prompt and mid-turn message, compacted ones
  included). Not named: refused; an agent file's own model is not used.
- Another model on the session's one-model server is refused; a one-request
  session model is not its own subagent, and nothing else is picked.
- The team is offered when a model could serve: the session's with two
  slots, or any usable model off its one-model server; the size note adds
  team_own when the session's model cannot serve its own.
- "Subagents" in /effort, /team, /settings and the config schema; the status
  bar reads "agents 3/4 · 2 subagents working".
- /context: used of the window, one bar by category, each category's share,
  what is free, and "N until auto-compact".
- Conformance runner for the subagents area (26 cases); helper -> task.

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

schema/connections.schema.json

@@ -210,11 +210,11 @@
                   "maxLength": 300
                 },
                 "single_session": {
-                  "description": "The server serves one request at a time: a subagent on this same model would take its only slot and push the session's cached prompt out, so it is refused. The same as parallel: 1.",
+                  "description": "The server serves one request at a time: a subagent on this same model would take its only slot and push the session's cached prompt out, so it is refused (name a model on another server instead). The same as parallel: 1.",
                   "type": "boolean"
                 },
                 "parallel": {
-                  "description": "How many requests the model's server serves at once (capacity.parallel); wins over single_session. Absent with no single_session: no limit (a hosted API). A team is offered only on a model that serves at least 2.",
+                  "description": "How many requests the model's server serves at once (capacity.parallel); wins over single_session. Absent with no single_session: no limit (a hosted API). The session's model is its own subagents' model only when it serves at least 2.",
                   "type": "integer",
                   "exclusiveMinimum": 0,
                   "maximum": 9007199254740991