feat(ipc): add memoized pattern subscriptions

[rrrodzilla]

IPC clients can now subscribe to families of registered broadcast names, such as Order*, without listing each type. The new pattern APIs preserve literal exact subscriptions and deliver once per connection when selectors overlap.

Routing memoizes deduplicated recipient sets in a bounded cache. Subscription mutations invalidate the cache under the same state lock used by forwarding, including unsubscribe, disconnect, and connection replacement. Pattern requests validate atomically and respect the existing request rate limiter. Pattern-only clients use subscriber idle timeouts.

This prepares workspace release 9.3.0 with additive request/response types and v2 frame tags. Older servers close connections receiving the new tags, so clients must upgrade their server before using pattern methods. Documentation covers syntax, limits, unsubscribe behavior, and best-effort delivery.

Validation:

• 30 subscription manager tests and five IPC integration tests, including JSON, MessagePack, actual broker forwarding, and types registered after subscription.
• Full workspace clippy with all targets and features: zero warnings.
• cargo-semver-checks against 9.2.1: 196 applicable checks passed.
• Full workspace nextest: 667 passed with all features; 466 passed without default features. Seven doctests passed.
• Full workspace clippy without default features: zero warnings. Changed Rust files pass rustfmt.
• Production documentation build and all 2,134 links passed. Linux and Windows CI must pass before publishing.