fix: flaky test relay_does_not_accept_when_not_at_terminus uses Location::random()

[sanity]

Problem

relay_does_not_accept_when_not_at_terminus (crates/core/src/operations/connect.rs:3084) uses Location::random() for the desired_location. Since Location::random() uses GlobalRng, which is process-global shared state:

1. When run concurrently with other tests, the RNG state differs, producing different locations
2. The random location may make self_loc the closest peer to desired_location, turning the relay into a terminus — the test then fails because it expects forwarding, not acceptance

Root Cause

Location::random() at line 3091 is non-deterministic when tests run in parallel.

Fix

Replace Location::random() with a fixed location that guarantees next_hop is closer to the target than self_loc. For example:

desired_location: next_hop.location().unwrap(),

This ensures the relay always has a closer peer and is never at terminus.

Reproduction

Run the full test suite; it fails intermittently:

cargo test -p freenet --lib  # fails ~5% of the time
cargo test -p freenet --lib relay_does_not_accept_when_not_at_terminus  # always passes alone

[AI-assisted - Claude]

[github-actions]

🤖 Auto-labeled

Applied labels:

• T-bug (98% confidence)
• P-medium (90% confidence)
• E-easy (90% confidence)
• A-developer-xp (95% confidence)
• A-networking (80% confidence)

Reasoning: The report describes a flaky test (non-deterministic behavior caused by use of process-global RNG), which is a bug in the test suite. The fix is straightforward (replace random with a deterministic/fixed location), so effort is low (E-easy). The issue affects developer experience and CI (A-developer-xp); it also touches peer/location logic in the networking/connect code (A-networking). Priority is medium because it intermittently breaks the test suite and impacts developers/CI but does not indicate a production security or data-loss problem.

Previous labels: none

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