clampTimeout resolved the per-tool default (bash 300s) whenever the agent
omitted `timeout` and only enforced the tool's own min/max, so the
tools.maxTimeout global ceiling — applied solely in sdk.ts on explicitly
numeric args — was bypassed on the common default-fallback path.
Thread maxTimeout into clampTimeout so the resolved effective timeout,
including the default path, is capped before the per-tool floor/ceiling
apply. Explicit values below the cap still win; maxTimeout <= 0 stays
no-cap. Applied at every call site (bash, eval, browser, debug, lsp,
fetch, and the session-level bash executor), and the bash clamp notice
now names the global ceiling when it is the binding limit.
Fixes#6294
roboomp