dsh-ima-kb-panel: Move IMA knowledge base to DSH sidebar, add pagination for large notes.

The DSH client plugin maintained by how8088 (v2.7.0, MIT) addresses two gaps in the IMA knowledge base: `get_doc_content` lacks pagination parameters, causing tens of thousands of words of notes to consume the entire context at once; browsing the knowledge base also incurs model context costs. The left sidebar provides two tabs: "Notes" and "Knowledge Base," where browsing, searching, and scrolling do not consume context. Seven read-only, rate-limited tools (`kb_list`, `kb_search`, `kb_read`, `kb_find`, `kb_space_list`, `kb_space_browse`, `kb_space_search`) are registered in the conversation. Content and personal knowledge bases are cached to `~/.dsh/cache/ima-kb-panel/`; on restart, only notes with modified timestamps are updated, while subscribed and shared knowledge bases are not persisted to disk. Credentials are managed via files or environment variables, and twelve configuration options are available in `cordis.patch.yml`.