merge origin/dev into issue-13770-tool-output-docs

Resolve conflict in packages/opencode/src/tool/shell/prompt.ts to combine
truncationGuidance helper (which omits the truncation note when truncation
is disabled) with the configurable defaultTimeoutMs from origin/dev.

Fix typecheck in tool/truncate.ts by narrowing the tool_output union before
reading max_lines and max_bytes.