chore: import OpenCode plugin

[mislavivanda]

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Summary by cubic

Imports the Daytona OpenCode plugin as a standalone package to run sessions inside Daytona sandboxes with per-project persistence, git syncing, and developer tools. This adds packages/opencode-plugin and enables sandbox-backed workflows with simple setup.

• New Features

  • Daytona session manager: create/reconnect/delete sandboxes per session; persist mappings under XDG data dir; auto-migrate sessions across projects; cleanup on session delete.
  • Git sync: allocate opencode/N branches, add numbered remotes, push/pull between host and sandbox; works with empty repos and falls back gracefully when git is unavailable.
  • Tools: bash (supports background), read, write, edit, multiedit, ls, glob, grep, getPreviewURL (with live preview links); lsp and patch stubs included.
  • UX: toast notifications, system prompt additions, and structured logging to ${XDG_DATA_HOME}/opencode/log/daytona.log. Repo path in sandbox is /home/daytona/project. Requires DAYTONA_API_KEY.

• Dependencies

  • Adds @daytona/sdk, @opencode-ai/plugin, xdg-basedir, zod; dev: typescript, @types/node.
  • Includes standalone tsconfig.json, .npmignore, and in-place TypeScript build (emits .js/.d.ts under .opencode/plugin).

^{Written for commit 388e32d. Summary will update on new commits.}

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