feat: update libscope CLI as monorepo meta-package

[RobertLD]

Summary

Part of #488. Update the root libscope package to function as a CLI meta-package that depends on all @libscope/* sub-packages, and move remaining orchestration code (src/LibScope.ts, file watcher, workspace utilities) here.

Problem / Motivation

Once the sub-packages are extracted, the root libscope package needs to be updated to depend on them rather than containing their code directly. It also remains the one justified "kitchen-sink" entry point — end users installing the CLI tool expect everything to work out of the box.

Proposed Solution

• Update root package.json to depend on all @libscope/* packages
• Move src/LibScope.ts (main orchestration class), src/core/watcher.ts, src/core/workspace.ts, and src/core/repo.ts into the CLI package (these are lifecycle/process-management concerns)
• Keep src/cli/ here as the Commander.js entry point
• Ensure all existing CLI commands continue to work by importing from the appropriate sub-packages

Acceptance Criteria

• Root libscope package depends on all @libscope/* sub-packages in its package.json
• All 30+ CLI commands pass integration tests after the migration
• src/LibScope.ts is the orchestration entry point and imports from sub-packages (not from internal src/core/ paths)
• npm install -g libscope installs the CLI and all sub-packages correctly
• dist/cli/index.js, dist/mcp/server.js, and dist/core/index.js continue to exist at their current paths for backwards compatibility

Out of Scope

• Changes to CLI command behaviour or flags
• Changes to the LibScope public API class interface

Technical Notes

• This is the last step — should be done after all sub-packages are extracted and publishing is set up
• src/LibScope.ts currently imports directly from src/core/ — all those imports need to point to @libscope/core instead
• Lifecycle modules to keep here: watcher.ts (chokidar), scheduler.ts (node-cron, moves from connectors or stays here), workspace.ts, repo.ts