Fix Apple Container sandbox resource limits

[penso]

Summary

• pass configured sandbox memory and whole-CPU limits to Apple Container using --memory and --cpus
• apply pids_max with Apple Container's native --ulimit nproc=<limit> syntax
• reject fractional Apple Container CPU quotas explicitly instead of silently weakening the requested limit
• document Apple Container version and CPU-granularity constraints

Closes #1188

Validation

Completed

• cargo test -p moltis-tools apple_container_run_args
• cargo fmt --all -- --check
• just lint
• container run --rm --cpus 2 --memory 512M ubuntu:25.10 true

Remaining

• ./scripts/local-validate.sh <PR_NUMBER>
• Live pids_max verification with Apple Container 0.9+; the local CLI is 0.8.0 and predates --ulimit

Manual QA

1. Install Apple Container 0.9 or newer and select backend = "apple-container".
2. Configure memory_limit = "1G", cpu_quota = 2.0, and pids_max = 512 under [tools.exec.sandbox.resource_limits].
3. Restart Moltis and run ulimit -u plus a command that forks child processes inside the sandbox.
4. Confirm the process limit is 512 and the command completes without Resource temporarily unavailable.
5. Set cpu_quota = 0.5 and confirm Moltis reports that Apple Container requires a positive whole CPU count.

[greptile-apps]

Greptile Summary

The PR now passes configured memory, whole-CPU, and process limits to Apple Container and validates unsupported CPU quotas before any container reuse.

• Tracks managed-files and resource-limit policy fingerprints so changed limits trigger container recreation.
• Records fingerprints for generated container names after successful creation or recovery.
• Adds resource-limit argument and validation tests and documents Apple Container compatibility constraints.

Confidence Score: 5/5

The PR appears safe to merge.

No blocking failure remains.

Important Files Changed

Filename	Overview
crates/tools/src/sandbox/apple.rs	Applies resource-limit validation before reuse and correctly records policy fingerprints on all successful generated-name paths, resolving both prior findings.
crates/tools/src/sandbox/containers.rs	Adds Apple Container memory, whole-CPU, and nproc arguments with explicit CPU validation.
crates/tools/src/sandbox/tests/apple.rs	Covers generated-name policy tracking, resource-limit argument construction, and fractional CPU rejection.
docs/src/sandbox.md	Documents Apple Container version requirements and whole-CPU granularity.

_{Reviews (3): Last reviewed commit: "fix(sandbox): retain policy after name r..." | Re-trigger Greptile}

[penso]

@greptile review

[codspeed-hq]

Merging this PR will degrade performance by 10.97%

⚠️ Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

❌ 1 regressed benchmark
✅ 38 untouched benchmarks
⏩ 9 skipped benchmarks¹

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Benchmark	BASE	HEAD	Efficiency
❌	session_history_path[default]	6 µs	6.7 µs	-10.97%

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

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_{Comparing almond-football (2cb77aa) with main (af26d7e)}

Footnotes

1. 9 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

[penso]

@greptile review

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

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