fix(deployer): grant baseline capabilities to every sandboxed Compose service

[dviejokfs]

Summary

• Every sandboxed Compose service was getting cap_drop: ALL with no capabilities granted back unless the operator explicitly opted the service into relaxed_capability_services (the "Elevated permissions" toggle). Those 5 capabilities (CHOWN, DAC_OVERRIDE, FOWNER, SETUID, SETGID) are exactly what nearly every official image's entrypoint needs to chown a data/cache directory and drop from root to a service user — not just database images, but ordinary ones too (e.g. plain nginx:alpine with no volumes at all). Without the opt-in, a totally standard compose stack reliably failed with "Operation not permitted" only after a full 300s readiness timeout.
• This set is a strict subset of Docker's own default capability set, so granting it to every sandboxed service by default matches Docker's out-of-the-box behavior rather than introducing new privilege.
• Removed the now-inert "Elevated permissions" per-service checkbox from the console (GitSettings.tsx) since it no longer changes anything; the relaxedCapabilityServices field/schema is kept only so older stored configs keep deserializing.
• Updated the pre-deploy advisory and the post-failure capability-denial remediation messaging (compose.rs, deploy_compose.rs) to reflect the new default and point at unsandboxed_services ("Disable sandbox") as the escape hatch for images that need capabilities beyond this default set.

Security review

A security-auditor pass confirmed this does not widen the sandbox's actual attack surface: the granted capabilities operate within a container's own mount/user namespace, cannot cross the :ro secrets bind-mount (kernel-enforced MS_RDONLY, independent of capabilities), and there is no shared cross-tenant volume/network for them to act on. privileged, host namespaces, and cap_add itself remain blocked in tenant-supplied compose files regardless.

Test plan

• cargo check --lib on temps-deployer, temps-deployments, temps-entities, temps-presets
• cargo test --lib on the same crates — all green (a few pre-existing Docker-network-pool-exhaustion failures on the local dev box are unrelated to this change)
• cargo clippy -- -D warnings clean
• cargo fmt --check clean
• Updated/added unit tests in compose.rs covering: both a DB image and a plain web-server image get the baseline capability set with no opt-in; a fully unsandboxed service gets no cap_drop/cap_add at all; capability_denial_remediation reflects the new default-granted message

[greptile-apps]

Greptile Summary

The PR grants a five-capability baseline to every sandboxed Compose service while preserving the remaining sandbox controls.

• Removes the obsolete per-service elevated-permissions control while retaining backward-compatible stored configuration.
• Updates deployment diagnostics and remediation guidance to direct genuinely incompatible services toward the existing sandbox exemption.
• Adds and updates tests covering baseline grants, unsandboxed services, and capability-denial messaging.

Confidence Score: 5/5

The PR appears safe to merge, with the capability change remaining bounded by existing Compose mount and sandbox controls.

The implementation consistently grants the intended baseline only to sandboxed services, leaves unsandboxed behavior unchanged, preserves legacy configuration compatibility, and aligns operator-facing diagnostics with the new behavior.

Important Files Changed

Filename	Overview
crates/temps-deployer/src/compose.rs	Applies the baseline capability set to all sandboxed services and consistently updates generation, diagnostics, and focused tests.
crates/temps-deployments/src/jobs/deploy_compose.rs	Removes obsolete opt-in guidance and updates deployment failure remediation for the new baseline.
crates/temps-entities/src/preset.rs	Retains the legacy capability field for deserialization compatibility while documenting that it is inert.
web/src/components/project/settings/GitSettings.tsx	Removes the obsolete elevated-permissions checkbox and explains the automatic baseline and sandbox escape hatch.

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