[leehack]

Summary

Prepares llamadart and all three Apple runtime companions at 0.19.0 (#1786). Release notes: the compacted 0.19.0 section.

Includes #1808 (LiteRT-LM repin to v0.19.1-1, desktop CPU embeddings, fixes #1367 and #1795): main at 12933a0a was merged into this branch (no rebase, so the head moved forward only) with changelog union turned off, and #1808's bullets were folded into the 0.19.0 section by hand.

Gates:

1. Independent exact-head audit of b56357b6: PASS (cleared, see below).
2. Maintainer approval is still required before merging. Merging publishes: release_on_prep_merge.yml publishes core 0.19.0 and then the three companions to pub.dev. Do not merge without explicit approval.

Production-readiness scope

• User-facing scope: release metadata and docs only. Runtime pins are already on main:

  • native llama.cpp v0.9.0
  • LiteRT-LM v0.19.1-1 (upstream v0.19.1)
  • stable-diffusion v0.3.0-3, unchanged
  • Web bridge v0.1.83
  • Web LiteRT-LM @litert-lm/[email protected]

  Apple companions move to 0.19.0, constrained to '>=0.19.0 <0.20.0'. llamaCppAppleCompanionVersion moves 0.18.1 → 0.19.0, the first companion release that pins v0.9.0.

• Supported platforms/paths: the documented support matrix, unchanged by this PR.

• Unsupported or intentionally unavailable paths: unchanged. Existing typed refusals and documented restrictions stay as they are.

• Out of scope / follow-ups:

  • genkit_llamadart and llamadart_model_store are versioned independently and not touched. genkit_llamadart 3.7.0 constrains llamadart: ^0.18.0, so moving it to 0.19 is a separate Genkit release.
  • Stale "source adoption does not publish / remains Adopt LiteRT-LM 0.19 native C API 1.0 and lifecycle/ASR contract #1677 gates" wording (Adopt LiteRT-LM 0.19 native C API 1.0 and lifecycle/ASR contract #1677 closed after shipping in 0.18.0) is fixed in MIGRATION.md, README.md, the getting-started and speech skills, the support matrix, native build hooks and the two doc/litert_lm_* pages. Qwen3 GPU qualification notes that still cite Adopt LiteRT-LM 0.19 native C API 1.0 and lifecycle/ASR contract #1677 (known platform issues, flutter-app skill, chat app README) are left as they are.

Completeness checklist

• The declared scope is implemented, including Adopt LiteRT-LM native v0.19.1-1 and qualify desktop embeddings #1808's 0.19.0 changelog wording.
• Unsupported combinations: N/A. No runtime behavior changes.
• README, install docs, companion READMEs, MIGRATION.md, skills, changelogs (core, docs and the three companions) and the docs changelog trim (0.17.x removed) are updated.
• Regression coverage: hook pin tests cover the companion version constant. Release-docs gates pass.
• Validation coverage registry: N/A. No public capability change in this PR.
• Security review: no secrets, tokens or signed URLs added.
• Follow-ups are listed above and tracked in #1786.

PR type guidance

• Release preparation: bumps versions, constraints, install snippets and lockfiles, and compacts the changelogs. It changes no pin itself; the v0.19.1-1 pins arrived from main via Adopt LiteRT-LM native v0.19.1-1 and qualify desktop embeddings #1808. The normal high-risk route applies.
• Feature PR / Bugfix PR / Docs-only PR: N/A. Release preparation.

Test Plan

Run with the pinned Flutter 3.47.1 SDK at b56357b6 / base 12933a0a.

• dart run tool/prepare_workspace.dart: no tracked changes.
• dart format --output=none --set-exit-if-changed .: 0 changed.
• dart analyze: no issues.
• check_platform_boundaries.dart: OK.
• dart test -p vm -j 1 --exclude-tags local-only (full): left to CI.
• dart test -p chrome --exclude-tags local-only: left to CI. No Web code changed.
• coverage-lib: N/A. The only lib/ change in this PR is a version constant.
• Other checks:
  • dart test -p vm -j 1 --exclude-tags local-only test/unit/tooling/ test/unit/hook/ with an isolated TMPDIR: 2,158 passed, 4 skipped, 6 failed. All 6 are windows_registry_qualification_test.dart, which needs pwsh (not installed on this macOS host); Windows CI runs them.
  • verify_release_docs_versions.dart, normal and --release-prep: both exit 0, run in a fresh --filter=blob:none clone at b56357b6 (the local clone has shallow stray llama.cpp tags).
  • check_webgpu_bridge_tag.dart: OK.
  • companion_pub_preflight.dart: OK for all three companions.
  • check_core_archive.py: pass, 1,878 files staged.
  • ./tool/docs/build_site.sh: OK, no broken links.
  • llamadart_litert_lm_flutter Package.swift: all 7 checksums match the v0.19.1-1 GitHub release asset digests.

Matrix Evidence

Matrix row	Scope covered	Platform / model / backend	Result	Evidence / notes
high-risk-exact-head-independent-qa	exact-head release audit	macOS host, pinned Flutter 3.47.1	PASS	Fresh-agent auditor, exact head b56357b6 (includes #1808): zero blocking findings, zero PR-caused P1. Mutations killed: llamaCppAppleCompanionVersion back to 0.18.1 fails native_release_pins_test.dart; widening the SD companion constraint fails verify_release_docs_versions --release-prep.
release-metadata-verification	versions, constraints, changelog promotion and trim	macOS host	PASS	Release-docs verifier, normal and --release-prep, bridge-tag gate and companion preflight
structured-output-adversarial	N/A	—	N/A	No parser, grammar or template change
litert-lm-v1-public-direct / -service / -speech	N/A	—	N/A	No LiteRT-LM code change in this PR; #1808's exact-head audit and GCE requalification carry the LiteRT-LM evidence
litert-lm-json-schema	N/A	—	N/A	No LiteRT-LM change

Review Notes

• Independent review status: PASS at b56357b6 by a fresh agent auditor session that took no part in the implementation (operator-owned); zero blocking findings.
• CI status / head SHA: all green on b56357b65b516379f203eb369cdbb71a6b9be203 (37 pass, 9 skipped): CI, LiteRT-LM Smoke, Validation bundles, Native Release Digests, Chat App HF PR Preview and High-Risk Readiness Advisory.

High-risk regression review

• Classification: high-risk (artifactConsumer, from lib/src/hook/native_release_pins.dart).
• Implementation task: #1786, branch release/prep-0.19.0.
• Independent blocking QA task: done. Fresh agent auditor session (not the PR author), blocking-only adversarial review of exact head b56357b6 against base 12933a0a: PASS, zero blocking findings.
• Exact head / current base: b56357b65b516379f203eb369cdbb71a6b9be203 / 12933a0abf2efee69699cd05a6bd16d912bd2545.
• Production-branch deletion, bypass, or miswire proof: N/A. The only production change is the companion-version constant, pinned by native_release_pins_test.dart, which derives the expected value from the companion changelog.
• Affected-family real-model/artifact evidence: N/A. This PR changes no pin. Runtime evidence comes from #1784, #1785, #1807 and #1808.
• Explicit unavailable-family or other N/A evidence: N/A. No runtime change.
• Known PR-caused P1 regressions: 0.
• Unresolved review threads: 0.
• Readiness evidence: v2 evidence for this head/base (tool/testing/high_risk_readiness.dart) is internally consistent and exits 2 (unverifiedPrerequisites), the expected local result; it is not operational readiness. Affected test: test/unit/hook/native_release_pins_test.dart (mutation control killed).
• Publication: merging publishes to pub.dev and still needs explicit maintainer approval.

[github-actions]

Chat app preview removed for leehack/llamadart-chat-pr-1812.