chore(deps): bump acp-kernel 0.0.28 -> 0.0.31

[ranxianglei]

Bundles three kernel releases since 0.0.28 (tsup inlines the kernel into dist, so this is the only way users get them):

0.0.29 — search performance

• Single-pass CJK segmentation + memoized per-doc features (perf)
• 2-char CJK queries admitted into fuzzy channel (Latin frozen)

0.0.30 — compress retry-loop fixes

• fc56e64 stale-refs gate message: when every range in a batch fails boundary resolution, the gate now reports stale refs instead of the misleading "content too small (0 chars)… combine more messages" — root cause of cross-turn compress retry loops (kernel commit cites billion-context-pi#178)
• 79340d3 snap consumed anchors to the active owning block

0.0.31 — wire fix

• 626f933 preserve all image_url parts in the OpenAI codec (multi-image)

Verification

• lockfile pins acp-kernel 0.0.31
• typecheck clean, 498/498 tests pass, build OK (dist/index.js 2.10 MB)
• dist/index.js contains the new stale-refs reporting (61 matches)

Notes

• Kernel feat: three-state update mode and fixed nudge growth interval #86 (decideNudge half-threshold dead code, tracked by 跟踪 acp-kernel#86:pending nudge 半阈值接线 — 升级-only 影响 / 适配方案 / 后果评估 #166) is not addressed in 0.0.29–0.0.31 — still OPEN upstream; this bump does not change that.