OptimizedNodeBridge should guard against negative/NaN timeoutMs

[bbopen]

Problem

timeoutMs is accepted without validation. If callers pass NaN, Infinity, or negative values, the per-request timeout timer may fire immediately or never fire, breaking timeout enforcement. NodeBridge has similar weak validation but timeoutMs is used more widely in OptimizedNodeBridge (queue wait, timeouts, TTL).

Evidence

• src/runtime/optimized-node.ts: timeoutMs assigned directly to options with no normalization; used in setTimeout and TTL calculations.

Acceptance criteria

• Normalize invalid timeoutMs to a safe default (e.g., 30000) or clamp to a minimum > 0.
• Add tests for NaN, Infinity, negative values.

[bbopen]

Resolved by PR #150. validators.ts provides assertPositive() to guard against negative/NaN values. BoundedContext.validatePositive() wraps this for bridge use.