fix: use milliseconds for bash timeouts

[K-Mistele]

Summary

• rename the Bash tool timeout input from timeout to timeout_ms
• interpret explicit timeouts in milliseconds, matching Claude Code and Codex shell conventions
• document milliseconds, the 120-second default, and the maximum in both the parameter and top-level tool descriptions
• update timeout validation, failure messages, and process-group timeout coverage

Why

Models were emitting values such as 120000 with millisecond intent, while Fold interpreted them as seconds. A two-minute timeout therefore became 33 hours and left sessions waiting on commands long after Riptide considered them inactive.

Historical session events remain readable because persisted tool-call parameters are stored as unknown data and are not re-executed during replay.

Validation

• bun --cwd packages/fold-agent test test/Tools/BashTool.vi.test.ts (21 passed)
• bun run --cwd packages/fold-agent typecheck
• bun run format:check