Record failed checks when speed testing is enabled

[DavidVoitenko]

Summary

• Save failed basic proxy checks immediately when optional speed or anonymity checks are configured. A failed basic check never enters the expensive stage, so deferring its write had left progress at zero and job items pending.
• Add a real socket regression with eight local proxy endpoints: each accepts TCP, seven never answer the target request, and one answers the target but stalls on the speed URL. The CLI now records all eight results and observations, leaves no pending job items, and records an error for the failed speed measurement.
• Prepare patch release 3.0.4 with updated version references and changelog.

Verification

• Before the fix, the focused regression showed Checked 0/8 and no saved rows; after the fix, it records 8/8.
• Full local suite: 3,723 tests passed, 2 skipped.
• The socket regression passes with warnings treated as errors.

Addresses #33. A working proxy whose speed download never responds still uses the configured speed probe timeout; the fix keeps all completed basic failures visible and durable.