feat: agent loop ledger (JSONL events with run IDs) on history and logs #2577

Goal

Persist loop events in a local, redacted, queryable ledger that reuses Base's run-ID and logging machinery.

Background

base_history and base_logs already provide run IDs, redaction, and reporting for command executions. Loop events should appear in the same evidence trail rather than a parallel one, so that handoff and metrics can be derived without new infrastructure.

Next-release planning review of 2026-10-14/15 against main at 7faf6dfb. Tracking: #2555.

Prerequisites: #2576.

Scope

• Append events conforming to the Run the manual issue review loop with maintainer escalation #2576 schema to a ledger under the Base cache layout (see docs/cache-ownership-and-layout.md).
• Reuse existing redaction; ensure no secrets or personal data reach the ledger.
• Expose via basectl history/logs filters or a thin agent log view.

Acceptance Criteria

• Events validate against the schema.
• Redaction tests cover tokens and environment values.
• Ledger paths follow the cache ownership document.

Validation

BASE_CLI_SOURCE_DIR=../base-cli/lib/python \
PYTHONPATH=../base-cli/lib/python:lib/python:cli/python \
python -m pytest cli/python/base_history/tests cli/python/base_logs/tests <new ledger tests>
git diff --check

Non-Goals

• No remote upload.
• No new telemetry service.

Project Fields

• Status: Backlog
• Priority: P2
• Area: CLI
• Initiative: Agentic Coding Platform
• Size: M
• Milestone: v1.12.0
• Category: enhancement

Agent Assignment

Assignee: codeforester. Blocked on #2576.

Plan revision (2026-10-16)

This remains a v1.12.0 ledger foundation. The JSONL writer must define append atomicity, partial-line recovery, corruption handling, run/event identity, and redaction boundaries clearly enough for #2582 replay. #2602 is the follow-on v1.13.0 issue for checkpoints, idempotency keys, GitHub readback, resume/abandon state, and interruption recovery; do not imply those guarantees are delivered by this issue alone.