fix(code-runtime): reject a maxWallMs above Node's maximum timer delay

`config.maxWallMs` is only checked for positivity, and it is handed to
`setTimeout`, which clamps any delay above 2^31-1 ms to 1 ms. A deployment
configuring a 25-day wall ceiling therefore gets the opposite of what it asked
for: every run times out on the first tick. The runtime now range-checks the
field at load against MAX_TIMER_DELAY_MS from dsh-timeout and throws, so the
misconfiguration fails loud where it is self-contained instead of silently
inverting the budget.

`computeMs` needs no matching bound: it is compared against measured event-loop
utilization rather than fed to a timer.

The test asserts both the rejection and that the boundary value itself loads.

docs/config-catalog.md

@@ -318,7 +318,7 @@ export interface Config {
 }
 ```
 
-Source: [`packages/code-runtime/code-runtime-worker/src/index.ts:24`](../packages/code-runtime/code-runtime-worker/src/index.ts)
+Source: [`packages/code-runtime/code-runtime-worker/src/index.ts:25`](../packages/code-runtime/code-runtime-worker/src/index.ts)
 
 ## `@deepseek-ai/dsh-compact-basic`