remove c0re.operatorPronouns and c0re.contextWindowTokens

Both options are now ignored with a warning (the swarm-peers-removed.nix
shape), so a host that still sets one keeps evaluating.

- operatorPronouns: the agents' system prompt names the pronouns as
  she/her, the value the harness fell back to and the option's default.
  The --operator-pronouns flag, HiveEnv field, meta-flake let binding
  and HIVE_OPERATOR_PRONOUNS env var are gone.
- contextWindowTokens: the per-family defaults (haiku 200000, sonnet
  1000000, opus 1000000) move into hive-agent's harness_state as a
  table; the window the API reports after a turn still wins. The
  --context-window-tokens flag, HiveEnv field and the rendered
  HIVE_CONTEXT_WINDOW_TOKENS_<KEY> env vars are gone.

nix/agent-modules/agent-service.nix

@@ -70,11 +70,9 @@ in
       `swarmctl agent inference set`) wins over this option.
 
       Valid values are the short model names that `claude --model` accepts:
-      `"haiku"`, `"sonnet"`, `"opus"` (or any future identifier). Context
-      window sizes are looked up at runtime from the
-      `HIVE_CONTEXT_WINDOW_TOKENS_<KEY_UPPER>` env vars injected by the
-      meta flake; override sizes via `services.hyperhive.c0re.contextWindowTokens`
-      on the host.
+      `"haiku"`, `"sonnet"`, `"opus"` (or any future identifier). The
+      harness takes the context window from the model's own report after
+      each turn, and from a per-family default before the first.
     '';
   };