Agents Upgrade Plan

feat: implement resumable command queue, automatic thought summaries, and queued execution controls to match Codex CLI session management and Claude Code’s scripted workflows
feat: add first-class prompt, agent, and sub-agent configuration via .owlen/agents plus reusable prompt libraries, mirroring Codex custom prompts and Claude’s configurable agents
feat: deliver official VS Code extension and browser workspace so Owlen runs alongside Codex’s IDE plugin and Claude Code’s app-based surfaces
feat: support multimodal inputs (images, rich artifacts) and preview panes so non-text context matches Codex CLI image handling and Claude Code’s artifact outputs
feat: integrate repository automation (GitHub PR review, commit templating, Claude SDK-style automation APIs) to reach parity with Codex CLI’s GitHub integration and Claude Code’s CLI/SDK automation