feat: add Oh My Pi (omp) launcher integration

[ahmedyounes]

What

Adds an Oh My Pi tile to the dashboard's Applications list that launches the oh-my-pi (omp) coding agent against the running oMLX server — a sibling of the existing Pi tile. Non-destructive: the Pi tile is unchanged.

Why

omp is a popular fork of pi-coding-agent with a coding-first workflow. Users who run omp instead of vanilla pi had no one-click way to point it at their local oMLX server.

How it works

omp is a separate binary from pi with its own config dir (~/.omp/agent), but it:

• honors the same PI_CODING_AGENT_DIR override, and
• reads custom OpenAI-compatible providers from ~/.omp/agent/models.yml using the same providers.<name> schema as pi — just YAML instead of JSON.

OhMyPiIntegration therefore reuses PiIntegration's provider schema but writes/merges models.yml (YAML) with the same read→backup→merge→write pattern as the Hermes integration, preserving any other providers the user already has, then execs omp --model omlx/<model>. (omp only auto-migrates models.json→models.yml when the latter is absent, so writing YAML directly is the robust path across relaunches.)

Changes

• New omlx/integrations/omp.py — OhMyPiIntegration; registered in omlx/integrations/__init__.py
• omlx/settings.py + omlx/admin/routes.py — omp_model setting (parity with the other tools)
• omlx/admin/templates/dashboard/_status.html — new tile; omlx/admin/static/js/dashboard.js — ompCommand getter + save/default wiring
• omlx/admin/static/img/integrations/omp.svg — icon (theme-aware π glyph matching the existing set)
• omlx/cli.py — launch help text
• tests/test_integrations.py — TestOhMyPiIntegration + registry assertions

Testing

• pytest tests/test_integrations.py → 101 passed (13 new omp cases mirroring the Pi suite + registry updates).
• Verified end-to-end against the real omp v15.8.0: the generated ~/.omp/agent/models.yml is accepted and omp --list-models omlx lists the configured model.
• Ran the server from source and confirmed the Oh My Pi tile renders in /admin/dashboard, and omlx launch list reports omp.