- export now shares _add_session_filter_args / build_prune_filters with
prune/archive: AGE grammar (5h/2d/1w/ISO) on --older-than plus the full
filter set (--model, --provider, --min-messages, --min-cost, --branch,
--chat-id, ...) for both JSONL and md/qmd bulk exports; --dry-run works
on JSONL too; removes the one-off list_export_candidates helper.
- new --redact flag runs exported message content and tool output through
force-mode secret redaction (agent.redact) for jsonl, md, and qmd.
- docs EN + zh-Hans updated; new tests for AGE grammar, extended filters,
filtered JSONL, and redaction.
