release v0.1.1

[ranxianglei]

Ships since v0.1.0

• fix(v1): normalize ref tag placement #12 ref tag normalization (placement fixes)
• fix(v1): preserve truncated tool result bodies #13 truncated tool-result bodies preserved
• fix: align system prompt with PI rules #14 system prompt aligned with PI rules
• feat(v1): prefer reported usage for nudge calculations #15 reported usage preferred for nudge calculations
• test: repair root smoke harness #16 smoke harness repair
• fix(v2): register tools with AI-SDK shape + idempotent system prompt #18 v2 tools registered with AI-SDK shape + idempotent system prompt
• core: filter status compressible ranges via billion-context-kit viableRanges #19 status compressible ranges filtered via billion-context-kit viableRanges; kit pinned to npm 0.1.1

acp-kernel stays at 0.0.19 this release (upgrade to 0.0.24 deferred to a dedicated PR — the 5-version jump crosses the prompts-interface + truncation API surface and deserves its own review).

54/54 tests, workspace typecheck clean, build green.