Fix plugin SDK CLI workspace dependency resolution

[karutoil]

Summary

The @catalyst/plugin-sdk-cli package (packages/plugin-sdk/cli/) declares @catalyst/plugin-sdk: workspace:* as a dependency, but it is NOT included in Bun's workspace resolution. The bun.lock has no entry for it, meaning the CLI cannot resolve its workspace dependency during development.

Current State

• packages/plugin-sdk/cli/package.json has "@catalyst/plugin-sdk": "workspace:*"
• Root package.json workspaces: ["catalyst-backend", "catalyst-frontend", "catalyst-shared", "catalyst-plugins/*", "packages/*"]
• packages/* should match packages/plugin-sdk but NOT packages/plugin-sdk/cli/ (nested subdirectory)
• bun.lock grep confirms no entry for @catalyst/plugin-sdk-cli
• Template packages also reference @catalyst/plugin-sdk ^0.1.0 (npm registry) instead of workspace version

Impact

• catalyst-plugin create may fail or use an outdated SDK version
• Plugin scaffolding produces projects with wrong SDK dependency
• Development workflow for the CLI is broken (cannot bun install and resolve workspace dep)

Fix Options

1. Add packages/plugin-sdk/cli/ to workspaces — explicit workspace entry
2. Move CLI into packages/plugin-sdk/ as a proper sub-package — already there structurally, just needs workspace config
3. Make CLI standalone — remove workspace:*, publish SDK to npm, CLI depends on npm version

Acceptance Criteria

• bun install resolves @catalyst/plugin-sdk-cli workspace dependency correctly
• catalyst-plugin create scaffolds a project that builds and runs
• Scaffolded projects reference the correct SDK version (workspace in dev, npm in production)
• Template package.json files use current SDK version, not ^0.1.0