feat: let the catalog declare a device, fixing Mysterium's missing TUN (CashPilot-6rv)

[GeiserX]

Closes the P1 behind the MystNodes failure documented in #155.

The gap

A service could declare cap_add but not a device, and the orchestrator had no device support at all. Mysterium needs /dev/net/tun to carry wireguard/dvpn traffic. Without it the node starts, registers, advertises itself to the network — and carries nothing.

Every view CashPilot had of it looked healthy. It took a provider email to surface. That is precisely the "running is not earning" case.

The fix

Service YAML now supports devices:, and mysterium.yml declares /dev/net/tun.

Deliberately not a passthrough

A device is a direct line to the kernel, so:

• A hard allow-list in the worker (_ALLOWED_DEVICES) that the catalog cannot widen. Adding an entry is a maintainer decision in code, not something a service YAML can do on its own.
• Per-slug scoping, the same rule already used for cap_add: a service may only request what its own YAML declares. With a union, one service declaring a device would grant it to the other 49.
• Unknown slug → empty set — deny, never fall back to the union.
• A host-path remap is judged on the host path, so /dev/mem:/dev/net/tun is refused rather than smuggled through on its container-side name.

Tests target the refusals

/dev/mem, /dev/kmsg, raw block devices, /dev/mapper/control, /dev/kvm, a traversal attempt, and the remap above — plus two structural guards:

• the catalog can never declare a device outside the ceiling (fails if someone adds one to a YAML)
• deploy_raw actually forwards it — a declaration nothing forwards would protect nobody

Verification

• ruff check . && ruff format --check . — clean
• pytest --cov=app --cov-fail-under=90 — 1470 passed, coverage 94.90%
• The guide's manual-workaround note is updated to say this is fixed, rather than leaving stale instructions behind.

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📥 Commits

Reviewing files that changed from the base of the PR and between fad13ec and 6826f62.

📒 Files selected for processing (8)

• CHANGELOG.md
• app/main.py
• app/orchestrator.py
• app/worker_api.py
• docs/guides/mysterium.md
• services/_schema.yml
• services/bandwidth/mysterium.yml
• tests/test_catalog_devices.py

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[codecov]

Codecov Report

❌ Patch coverage is 94.11765% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 94.23%. Comparing base (fad13ec) to head (6826f62).

Files with missing lines	Patch %	Lines
app/worker_api.py	94.11%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #157      +/-   ##
==========================================
- Coverage   94.23%   94.23%   -0.01%     
==========================================
  Files          36       36              
  Lines        4475     4492      +17     
==========================================
+ Hits         4217     4233      +16     
- Misses        258      259       +1     

Files with missing lines	Coverage Δ
app/main.py	96.85% <ø> (ø)
app/orchestrator.py	75.98% <ø> (ø)
app/worker_api.py	87.53% <94.11%> (+0.31%)	⬆️

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