feat(pi-harness): make pi-harness a standalone publishable package

[arjun-zosma]

Summary

Makes pi-harness a standalone npm package (like create-openzosma) so it can be published without relying on the unpublished @openzosma scope.

Problem

Publishing @openzosma/pi-harness fails because:

1. The @openzosma npm scope doesn't exist (or the token lacks access)
2. It depends on unpublished workspace packages: @openzosma/agents and @openzosma/logger

Changes

• Renamed package: @openzosma/pi-harness → pi-harness
• Inlined logger: Created a minimal src/logger.ts to replace @openzosma/logger dependency
• Removed workspace deps: @openzosma/agents and @openzosma/logger removed from package.json (agents code is already bundled by esbuild)
• Updated build script: build-bundle.mjs now bundles server.ts and cleans up internal session-manager files that referenced workspace packages
• Added metadata: license, keywords, and repository fields to `package.json"

Verification

cd packages/pi-harness
pnpm build
npm pack --dry-run
# → name: pi-harness
# → no @openzosma runtime imports in dist/