SDK sausage-actor; examples and agent on the SDK; agent without limits

- sausage-actor: Message, messages(), send/reply/publish, async Inbox
- agent: append-only /data/history.jsonl, no caps on history, steps, waits,
  tool output, or reads; max_tokens only when configured (Anthropic: 32000)

Cargo.lock

@@ -15,7 +15,7 @@ dependencies = [
 name = "agent"
 version = "0.1.0"
 dependencies = [
- "async-channel",
+ "sausage-actor",
  "serde",
  "serde_json",
  "wstd",
@@ -1601,6 +1601,12 @@ dependencies = [
 [[package]]
 name = "sausage-actor"
 version = "0.1.0"
+dependencies = [
+ "async-channel",
+ "serde",
+ "serde_json",
+ "wstd",
+]
 
 [[package]]
 name = "scopeguard"