Clean up old plugin versions from cache after auto-update

[kaghni]

Summary

• After a successful auto-update, removes all old cached version directories, keeping only the newly installed version
• Applies to both Claude Code (~/.claude/plugins/cache/hivemind/hivemind/) and Codex (~/.codex/plugins/cache/.../hivemind/) caches
• Cleanup failures are logged but never block the session

Test plan

• Typecheck passes
• Build succeeds
• Simulated cache cleanup correctly removes old dirs and keeps latest

[claude]

Claude finished @kaghni's task in 3m 37s —— View job

---

Review

• Codex cleanup deletes the newly-updated plugin (src/hooks/codex/session-start.ts lines 200–215): The Codex update copies files in-place into the existing versioned directory (e.g. 0.6.22/), which keeps its old name. e.name !== latest ("0.6.22" !== "0.6.23") is always true, so the block deletes the freshly-updated plugin every time. Fix this →
• Cleanup runs even when the update silently failed: findCmd always exits 0 (the last command, rm -rf "$TMPDIR", succeeds regardless of whether git clone worked), so execSync(findCmd) never throws. This cleanup can wipe existing plugin dirs when the underlying update never actually installed anything.

The Claude Code path (src/hooks/session-start.ts) looks correct — claude plugin update is a proper package manager that creates a new versioned directory, so keeping only latest and discarding old ones is safe there.

---

[claude]

The Codex update copies files in-place into the existing version directory (which keeps its old name, e.g. "0.6.22"), so e.name !== latest ("0.6.22" !== "0.6.23") is always true — this block will delete the freshly-updated plugin on every successful auto-update, leaving the cache empty. Additionally, findCmd always exits 0 (the final rm -rf "$TMPDIR" succeeds even when git clone fails), so execSync(findCmd) never throws and this cleanup can also wipe existing plugin dirs when the update silently failed.

Remove this cleanup block for Codex — the in-place copy strategy never creates a new versioned directory, so there is nothing stale to remove.

Suggested change

	// Clean up old cached versions
	try {
	const cacheBase = join(homedir(), ".codex", "plugins", "cache");
	const hivemindDirs = execSync(`find "${cacheBase}" -maxdepth 3 -name "hivemind" -type d 2>/dev/null`, { encoding: "utf-8" }).trim().split("\n").filter(Boolean);
	for (const hDir of hivemindDirs) {
	const entries = readdirSync(hDir, { withFileTypes: true });
	for (const e of entries) {
	if (e.isDirectory() && e.name !== latest) {
	rmSync(join(hDir, e.name), { recursive: true, force: true });
	log(`cache cleanup: removed old version ${e.name}`);
	}
	}
	}
	} catch (e: any) {
	log(`cache cleanup failed: ${e.message}`);
	}
	// Codex update is in-place (files copied into the existing versioned dir);
	// no stale version directories are created, so no cache cleanup is needed.