docs(spikes): fix math error and UAPI protocol name in wireguard spike - #490

Two post-merge correctness issues found by sdd-review on PR #488:

Changes

MEDIUM — Arithmetic fix (line 88 + action item 4)

The boringtun release gap (0.6.0 July 2023 → 0.7.0 January 2026) is ~30 months (~2.5 years), not ~18 months. The arithmetic:

• July 2023 + 18 months = January 2025
• July 2023 + 30 months = January 2026 ✓

The incorrect figure propagated into action item 4's risk-register checkpoint: "re-evaluate if no version is released within 18 months of the prior release." That threshold was calibrated against the wrong gap and would have triggered for any 19-month silence even though the historical gap was 30 months. Both occurrences are corrected.

LOW — Protocol name fix (line 71)

wireguard-go's subprocess interface is the WireGuard UAPI protocol — a line-based key=value text protocol over a Unix socket — not a "JSON configuration socket." Updated to "UAPI socket (a line-based key=value text protocol over a Unix socket)" for accuracy.

Proof

File assertion: docs/spikes/2026-06-20-wireguard-implementation.md contains no 18-month or JSON configuration text after this change, and contains ~30-month gap at lines 89 and 250, and UAPI socket at line 71.

$ grep -n '18.month\|JSON configuration' docs/spikes/2026-06-20-wireguard-implementation.md
(no output)
$ grep -n '30.month\|UAPI' docs/spikes/2026-06-20-wireguard-implementation.md
71:    via its UAPI socket (a line-based key=value text protocol over a Unix
89:  pace had an ~30-month gap between 0.6.0 (July 2023) and 0.7.0 (January 2026,
250:4. **Risk register entry:** Note that boringtun exhibited an ~30-month release
255:   30 months of the prior release.

Refs #488

Generated by sdd-execute (sonnet tier) for issue #488 · ◷

Summary by CodeRabbit

• Documentation
  • Refined WireGuard implementation technical documentation with updated specifications for integration approaches and protocol details.
  • Clarified architecture descriptions to improve accuracy of technical implementation information.
  • Adjusted maintenance timeline expectations and updated risk assessment checkpoints to better reflect expected maintenance cadence and evaluation criteria.