release v0.1.90

[ranxianglei]

release v0.1.90

Version-only release commit on top of master. Ships 11 PRs merged since v0.1.89.

⚠️ This release doubles as the §5 no-op-validation hop for #613 — none of the included changes touch src/update.ts, so the 0.1.89 → 0.1.90 upgrade exercises the v0.1.89 updater code end-to-end. #613 (updater egress proxy) merges only after this hop is observed succeeding.

Changes since v0.1.89

PR	Change
#607	chore: bump acp-kernel to 0.0.56 (fixes acp_status tool-result bucket attribution, #386)
#608	test: wire-exit enumeration matrix — compile-time registry + abort/in-band-error cells (#588)
#578	docs: correct false renumber claim in preflight comment (#595/#387)
#481	fix(launcher): fail fast when spawned proxy child exits pre-bind (#596)
#442	chore(#436): log context-window source per model — diagnostic (#597)
#522	fix: skip dead-pid proxy-origin records in MCP shell origin resolution (#599)
#494	docs: record kernel id-immutability contract in AGENTS.md (#600)
#614	docs: drop stale kernel-bump guard from AGENTS.md
#610	fix: salvage single-quoted compress args before hard rejection (#603)
#611	fix: arm emergency shrink on upstream 5xx/network failure (#604)
#612	test: wire-exit gap cells — preflight-emitter shapes, post-commit JSON errors, abort-storm convergence (#588)

Pre-flight

• typecheck ✓
• tests 1192/1194 (2 known env fails in plugin-agent.test.ts, environment-only) ✓
• build ✓

[github-actions]

📦 Built Package Artifact

Branch: 2026-09-07_release-v0.1.90 (8acad91)

Option A — Install from npm PR tag (recommended)

npm install -g billion-context@pr-620

Each push to this PR publishes a new version under the pr-620 npm tag.

Option B — Download artifact

1. Download the artifact from the Actions run
2. Extract the tarball and install:

tar xzf billion-context-pr620.tgz
npm install -g package

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This comment is automatically updated on each push.