fix: protect orchestrators from session cleanup

[harsh-batheja]

Summary

• harden core cleanup selection so canonical orchestrator sessions are always skipped, even when stale worker-like metadata or archived OpenCode mappings exist
• filter orchestrator entries out of ao session cleanup output and counts so worker cleanup stays visible without surfacing orchestrator cleanups
• add regression coverage for active and archived orchestrator metadata, dry-run/output filtering, and cross-project prefixed cleanup results

Verification

• corepack pnpm --filter @composio/ao-core test -- session-manager.test.ts
• corepack pnpm --filter @composio/ao-cli test -- session.test.ts session-utils.test.ts
• corepack pnpm --filter @composio/ao-core typecheck && corepack pnpm --filter @composio/ao-cli typecheck
• corepack pnpm -r --filter @composio/ao-cli... build

[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

^{Bugbot Autofix is OFF. To automatically fix reported issues with cloud agents, enable autofix in the Cursor dashboard.}

[harsh-batheja]

Addressed Cursor Bugbot feedback in commit e6bc6a8 by removing the redundant/unreachable duplicate orchestrator cleanup guard branch in packages/core/src/session-manager.ts. Re-ran core verification and pushed; all PR checks are now green.