Ralph loop stops after compaction due to lost in-memory state

[elecnix]

Problem

When pi performs compaction (auto-compaction or /compact), the Ralph Wiggum loop silently stops working. The agent continues, but ralph_done returns "No active Ralph loop" and the iteration counter freezes.

Root Cause

The extension maintains loop state in two places:

1. On-disk (persistent): .ralph/<name>.state.json tracks status, iteration count, etc.
2. In-memory (ephemeral): A closure variable let currentLoop: string | null = null tracks which loop is active.

When compaction happens, the session reloads and the extension module is re-initialized, resetting currentLoop to null. The on-disk state remains intact, but the extension has no reference to it.

The session_start handler finds active loops on disk and notifies the user, but never restores currentLoop:

pi.on("session_start", async (_event, ctx) => {
    const active = listLoops(ctx).filter((l) => l.status === "active");
    if (active.length > 0 && ctx.hasUI) {
        const lines = active.map(/* ... */);
        ctx.ui.notify(`Active Ralph loops:\n${lines.join("\n")}\n\nUse /ralph resume <name> to continue`, "info");
    }
    updateUI(ctx);  // currentLoop is still null here
});

After this, all currentLoop-dependent code silently fails:

• ralph_done: returns "No active Ralph loop"
• agent_end: early-returns without checking completion markers
• before_agent_start: early-returns without injecting loop instructions

Proposed Fix

Restore currentLoop from disk state in the session_start handler:

pi.on("session_start", async (_event, ctx) => {
    const active = listLoops(ctx).filter((l) => l.status === "active");
    if (active.length > 0) {
        // Restore currentLoop from disk state (critical for surviving compaction)
        if (!currentLoop) {
            currentLoop = active[0].name;
        }
        if (ctx.hasUI) {
            const lines = active.map(/* ... */);
            ctx.ui.notify(`Active Ralph loops:\n${lines.join("\n")}\n\nUse /ralph resume <name> to continue`, "info");
        }
    }
    updateUI(ctx);
});

This ensures that after compaction (or any session reload), the first active loop found on disk is restored as currentLoop, allowing ralph_done and agent_end to function correctly.

Alternative Considerations

• If multiple loops are active, restoring active[0] may not be the one the user was working on. A more robust solution might track a "last active" loop or use a dedicated session_compact handler.
• Consider using pi.appendEntry() to persist loop state in the session itself, making it survive compaction without relying on the session_start rehydration path.