feat: add memoize middleware, drop parking_lot dep

CHANGELOG.md

@@ -86,6 +86,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/2.0.0.
   turn sees it. The verifier impl (`cargo check`, `tsc`) is
   domain-specific and supplied by the consumer; loopctl ships only the
   trait and the middleware.
+- `MemoizingMiddleware` and `PathExtractor` trait
+  (`middleware::memoize` module): opt-in middleware that caches
+  successful tool-call results keyed on `(tool_name, hash(canonical
+  input))` and returns cached output with a `[cached]` marker on hit.
+  Path-aware invalidation via the caller-supplied `PathExtractor` trait;
+  TTL-based expiry per `ttl_turns`. Default-off; only successful results
+  are cached.
 
 ### Changed
 
@@ -107,6 +114,13 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/2.0.0.
   grammar-aware samplers. Default `ToolConstraint::None` reproduces prior
   behaviour exactly; when `response_format` is also set, it wins and
   `tool_constraint` is ignored.
+- Removed `parking_lot` dependency entirely. All `parking_lot::Mutex`
+  usages migrated to `std::sync::Mutex` with the
+  `.unwrap_or_else(std::sync::PoisonError::into_inner)` recovery pattern.
+  The crate now uses a single mutex family with no external lock
+  dependency.
+- MSRV bumped from 1.85 to 1.94. The crate uses let-chain syntax
+  (`if x && let Some(y) = ...`) which stabilized in Rust 1.88.
 - Both sequential and parallel tool dispatch now check the cancel signal
   between calls. Previously, a Ctrl-C during a multi-tool batch was only
   honored at the next turn boundary; now it aborts the remaining calls in the

Cargo.toml

@@ -10,7 +10,7 @@ documentation = "https://docs.rs/loopctl"
 keywords = ["agent", "framework", "llm", "loop"]
 categories = ["api-bindings", "development-tools"]
 readme = "README.md"
-rust-version = "1.85"
+rust-version = "1.94"
 
 [lib]
 name = "loopctl"
@@ -27,7 +27,6 @@ tokio-util = { version = "0.7", features = ["rt"] }
 uuid = { version = "1", features = ["v4", "serde"] }
 tracing = "0.1"
 
-parking_lot = "0.12"
 reqwest = { version = "0.13", default-features = false, features = ["json", "stream", "rustls"], optional = true }
 async-stream = { version = "0.3", optional = true }
 httpdate = { version = "1", optional = true }