Extend CLI batch with structured input, configurable budgets, and bounded parallel reads

[Widthdom]

Summary

The CLI batch runner is safe but inflexible for generated audit pipelines and needlessly serial for independent read-only work.

Integrated v1.39.4 findings

• Support bounded parallel execution for independent read-only batch queries
• Make batch input and output budgets configurable within safe maxima
• Accept structured command objects in batch input

Evidence

batch accepts only JSON string arrays and rejects an object such as { "command": "status" }. It hard-codes 1,024 input lines and 10,485,760 output characters, and executes independent read-only queries serially through one connection.

Expected behavior / direction

Accept a validated structured command/args form, expose configurable budgets within safe maxima, and add an opt-in bounded parallel mode or planner for independent read-only items. Preserve stable per-item output, cancellation, and error isolation.

Related closed issues

• Fix batch output contract for machine-readable per-line results #4142 defined machine-readable CLI batch output.
• Process independent JSON-RPC batch items with bounded concurrency #4545 added bounded concurrency to JSON-RPC batches; this issue concerns the separate CLI batch runner.

These issues remain closed; this is a new regression or follow-up observed on v1.39.4.

Environment

Reproduced with a locally built cdidx v1.39.4 from current origin/main at 87b8bf44210344f52ba4cb7827c149dfad32c0c8, using a fresh repository index on macOS arm64.

[Widthdom]

Work started on branch fix-issue4723.