feat(paseo-omp): make composer pills configurable

[omercnet]

Summary

• add host-scoped preferences for the MCP, Hub, Memory, Sessions, and Quota composer pills
• expose five default-on toggles in a global-only Composer tab in the OMP sidebar
• reconcile pill registrations without rebuilding unaffected pills and skip disabled Hub/Quota polling
• preserve profile-aware MCP and quota behavior from current main
• add repository-level guidance protecting the live Paseo daemon during plugin development

Verification

• npm run typecheck
• npm run check
• npm test (675 passed, 3 skipped)
• isolated daemon at a dynamically assigned loopback port using paseo-omp/.paseo-dev
• verified paseo-omp loaded from the current checkout and reported running
• created an isolated omp-plugin agent, disabled Memory in OMP → Composer, and confirmed the live Memory pill disappeared while MCP and Sessions remained
• restored Memory and verified the Composer settings at 430px width with five switches and no horizontal overflow

No package version or changelog files were edited; Release Please owns release bookkeeping.