[leehack]

Summary

Prepares llamadart and all three Apple runtime companions at 0.19.1. Release notes: the compacted 0.19.1 section.

Stacked on #1843 (0.19.1 batch: #1830, #1831, #1833, #1839, #1840, #1841, #1842). Cut from #1843's head 810d9a29. #1843 has rebase-merged, and this PR is now retargeted to main. main at 1fdc222f is merged in as a638c0f6, with changelog union turned off locally, no rebase and no force-push. The three changelog conflicts resolve to the audited fec9bdc4 content, and no ## Unreleased heading remains. git diff origin/main a638c0f6 is byte-identical to git diff 810d9a29 fec9bdc4: same patch-id 04de3f12, same --stat (20 files, +85/-42). Release automation fires only on merge into main.

Gates:

1. Independent pre-audit at e2d60d9a: PASS. No P1 or P2, the LiteRT-LM companion floor >=0.19.1 was confirmed as required, and release automation was simulated OK. Its one P3 (the LiteRT-LM embeddings fail on Linux arm64 and crash on Windows x64 (all v0.18 pins) #1367 bullet wording) is fixed at fec9bdc4. Exact-head re-audit at a638c0f6 against main 1fdc222f: PASS, by a fresh independent session. The diff is byte-identical to the pre-audited prep, the fec9bdc4 wording was verified against code, release automation was simulated (no tags; pub.dev 0.19.1 returns 404 for all four packages; preflight OK), 36 checks pass and there are 0 unresolved threads.
2. Maintainer approval is required before merging. Merging into main publishes: release_on_prep_merge.yml publishes core 0.19.1, then the three companions, to pub.dev.

Production-readiness scope

• User-facing scope: release metadata and docs only. Runtime pins arrive with 0.19.1 batch: #1830 #1831 #1833 #1839 #1840 #1841 #1842 #1843:

  • native llama.cpp v0.9.0 (unchanged)
  • LiteRT-LM v0.19.1-2 (from Require the in-process LiteRT marker for Linux and Windows LiteRT-LM embeddings #1830)
  • stable-diffusion v0.3.0-3 (unchanged)
  • Web bridge v0.1.83 (unchanged from 0.19.0)
  • Web LiteRT-LM @litert-lm/[email protected] (unchanged)

  All three Apple companions move to 0.19.1 (Flutter floor >=3.38.6 from Raise the Apple companions' Flutter floor to 3.38.6 (#1834) #1841). Deviation from the plan: llamadart_litert_lm_flutter now requires llamadart: '>=0.19.1 <0.20.0' instead of keeping >=0.19.0. With >=0.19.0, verify_release_docs_versions.dart --release-prep fails: published core 0.19.0 pins v0.19.1-1 and keeps macOS LiteRT-LM in the hook cache beside a v0.19.1-2 companion. This matches the 0.16.2 precedent. Core 0.19.1 still accepts the published 0.19.0 companion (an earlier v0.19.1 rebuild) with an upgrade warning. The llama.cpp and SD companions keep '>=0.19.0 <0.20.0', because their pins are unchanged. llamaCppAppleCompanionVersion stays 0.19.0, the first companion pinning v0.9.0.

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

• Unsupported or intentionally unavailable paths: unchanged. The typed refusals from Require the in-process LiteRT marker for Linux and Windows LiteRT-LM embeddings #1830/Refuse LiteRT-LM GPU on Linux when every Vulkan device is software #1831 are documented in the changelog.

• Out of scope / follow-ups:

  • genkit_llamadart and llamadart_model_store are versioned independently and not touched. The ^0.19.0 companion snippets in the genkit README still admit 0.19.1.
  • MIGRATION.md gets a short 0.19.0 -> 0.19.1 entry, because release-workflow.md asks for one when breaking behavior changes. Default users are unaffected, since the bundled runtime moves to v0.19.1-2, but custom-runtime users need v0.19.1-2 or later for Linux and Windows embeddings: an explicit v0.19.1-1, which worked in 0.19.0, is now refused.

Completeness checklist

• The declared scope is implemented.
• Unsupported combinations: N/A. No runtime behavior changes in this PR.
• README, install docs, companion READMEs, MIGRATION.md, changelogs (core, docs and the three companions) and the maintainer companion handoff note are updated. The docs changelog is not trimmed (patch release).
• Regression coverage: the release-docs gates pass. The constraint mutation (LiteRT-LM floor back to >=0.19.0) fails --release-prep.
• Validation coverage registry: N/A. No public capability change in this PR.
• Security review: no secrets, tokens or signed URLs added.
• Follow-ups: None.

PR type guidance

• Release preparation: bumps versions, the LiteRT-LM companion floor, install snippets and lockfiles, and promotes and compacts the changelogs. It changes no pin, Package.swift, hook code or .gitattributes. The normal high-risk route applies.
• Feature PR / Bugfix PR / Docs-only PR: N/A. Release preparation.

Changelog compaction (## Unreleased -> ## 0.19.1, both core changelogs)

• The bridge-tag baseline line comes first: v0.1.83 (unchanged from 0.19.0).
• Merged "Adopt native LiteRT-LM v0.19.1-2" with the LiteRT-LM embeddings fail on Linux arm64 and crash on Windows x64 (all v0.18 pins) #1367 embeddings-marker refusal, a follow-up of the same pin. As of fec9bdc4, the bullet states the floor plainly: v0.19.1-2 or later, the bundled runtime. An explicit older LLAMADART_LITERT_LM_LIB_DIR runtime, including v0.19.1-1, is refused.
• Merged the Apple companions declare flutter >=3.38.0 but need Dart ^3.10.7 (Flutter >=3.38.6) #1834 Flutter-floor bullet into one "Release all three Apple runtime companions at 0.19.1" bullet, which also records the LiteRT-LM companion's v0.19.1-2 pin and core floor.
• The Small follow-ups after 0.19.0 (audit P3s, test gaps, doc nits) #1815 libLiteRt bullet no longer names the v0.19.1-1 runtime, which this release replaces.
• Bullets are ordered with LiteRT-LM first. Each one has one issue link.
• Added a runtime baseline paragraph in the 0.19.0 format, with LiteRT-LM v0.19.1-2.
• Missing-bullet sweep of v0.19.0..810d9a29 (main plus 0.19.1 batch: #1830 #1831 #1833 #1839 #1840 #1841 #1842 #1843): no user-visible change lacks a bullet.
  • Sweep #1815 tooling, test and migration-doc follow-ups (A) #1817, Fix multi-line native pin changelog replacement and stale model-store CI comment #1818, Pin the native pin changelog over-consumption guards with tests #1826, Sweep #1815: macOS LiteRT-LM smoke, model-store floors, closed-stdout supervisor echo #1828, Pin LFM2 raw inner-quote tool arguments across streaming splits #1829, Recover Flutter Chrome tests stalled on a lost Browser.close reply #1832, Stop native pin changelog continuation only at real Markdown headings #1835, 0.19.1 follow-ups from audits #1837/Pin Windows pending-delete removal for remove and prune (#1837) #1839/Pin Chrome supervisor exit precedence and post-done wait (#1837 a-d) #1840: tests, CI or tooling only. Pin Windows pending-delete removal for remove and prune (#1837) #1839's lib/ change is comments only.
  • Move genkit_llamadart compatibility to llamadart 0.19 #1816, Release genkit_llamadart 3.8.0 #1822, Pair the Genkit docs with genkit_llamadart 3.8.0 and llamadart 0.19.0 #1823: Genkit, which has its own changelog.
  • Record LiteRT-LM thinking as N/A for bundle templates that cannot think #1833, Explain which chat template LiteRT-LM bundles render (#1836) #1842: docs only (model-families and skills notes on LiteRT-LM bundle templates).
  • No bullet was dropped.

Test Plan

Run with the pinned Flutter 3.47.1 SDK (Dart 3.13.1) at e2d60d9a, base 810d9a29, each with an isolated TMPDIR. At fec9bdc4 (changelog wording and MIGRATION.md only), these were rerun and pass: format, both verify_release_docs_versions modes (full-history clone), check_webgpu_bridge_tag, build_site.sh, and the tool/ci/markdown_test_suites.txt root suites (729 passed, 3 skipped).

• 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): 11,647 passed, 129 skipped, 6 failed. All 6 are in windows_registry_qualification_test.dart and need pwsh, which is not installed on this macOS host (the same as Prepare 0.19.0 release #1812). CI runs them.
• dart test -p chrome --exclude-tags local-only: 4,635 passed, 1 skipped.
• coverage-lib: N/A. No lib/ change in this PR.
• Rerun at the merged head a638c0f6, all passing:
  • prepare_workspace: clean.
  • format, analyze and check_platform_boundaries.
  • verify_release_docs_versions, normal and --release-prep, in a full-history clone.
  • check_released_changelog_sections in PR mode for release/prep-0.19.1 against main.
  • companion_pub_preflight.
  • check_core_archive.py (1,882 files).
  • Classifier: high-risk, artifactConsumer.
• Other checks:
  • verify_release_docs_versions.dart: normal and --release-prep both exit 0, in a fresh full-history --filter=blob:none clone, because the local clone is shallow.
  • check_released_changelog_sections.dart with a simulated pull_request event: exits 0 for head release/prep-0.19.1 (prep exemption) and fails for a non-prep head ref, as expected.
  • check_webgpu_bridge_tag.dart: OK.
  • companion_pub_preflight.dart: OK for all three companions.
  • check_core_archive.py: pass, 1,882 files staged.
  • ./tool/docs/build_site.sh --port 18391: OK, no broken links.
  • validation_coverage_test.dart: passed (in the full VM run).
  • Lock regeneration through pub only: example/chat_app, packages/llamadart_validation and website/examples/observability change only their local core and companion versions.

Matrix Evidence

Matrix row	Scope covered	Platform / model / backend	Result	Evidence / notes
high-risk-exact-head-independent-qa	exact-head release audit	macOS host	PASS	Pre-audit PASS at e2d60d9a, with its P3 fixed at fec9bdc4. Exact-head re-audit PASS at a638c0f6 against main 1fdc222f: diff byte-identical, automation simulated, 0 threads, 0 PR-caused P1. Classifier: high-risk (artifactConsumer, from the root and companion pubspec.yaml/README/CHANGELOG files).
release-metadata-verification	versions, constraints, changelog promotion	macOS host	PASS	verify_release_docs_versions --release-prep exits 0 (full-history clone). verify_release_docs_companion_pins_test.dart is in the full VM run.
release-companion-pub-gate	companion pub.dev availability and constraints	pub.dev API	PASS (pre-merge)	0.19.0 is live (200) and 0.19.1 is absent (404) for core and all three companions, as expected before merge. The preflight passes. Automated-publishing admin settings cannot be checked from here.
release-representative-smokes	representative examples	macOS host	PASS (partial)	check_core_archive.py resolves and analyzes the packaged basic example and a fresh consumer. No model-backed smoke for this metadata-only PR.
genkit-release	N/A	—	N/A	Genkit not touched. Its routing and staging tests run in the full VM suite.
android-release-device-pool	N/A	—	N/A	No Android runtime change in this PR. The LiteRT-LM v0.19.1-2 Android evidence belongs to #1830 and its #1843 audit.
structured-output-adversarial, litert-lm-v1-public-*, litert-lm-json-schema	N/A	—	N/A	No parser, grammar, template or LiteRT-LM code change in this PR.

Review Notes

• Independent review status: pre-audit PASS at e2d60d9a by a fresh auditor session. The P3 follow-up is at fec9bdc4. Exact-head re-audit PASS at a638c0f6 against main 1fdc222f by a fresh independent session (operator-owned), with zero blocking findings.
• CI status / head SHA: CI does not run on PRs whose base is not main, so CI was dispatched on e2d60d9a: success (26 jobs passed, 6 skipped). A dispatched rerun on fec9bdc4 hit GitHub release-asset 504s, which was infrastructure, not this change. At the merged head a638c0f6 all PR checks pass (36 pass, 9 skipped): CI, LiteRT-LM Smoke, Validation bundles, Chat App HF PR Preview and High-Risk Readiness Advisory. The released-changelog check now runs as a PR check in Analyze & Lint and passes.

High-risk regression review

• Classification: high-risk (artifactConsumer).
• Implementation task: 0.19.1 release prep, branch release/prep-0.19.1.
• Independent blocking QA task: pre-audit PASS at e2d60d9a (no P1 or P2; one P3 fixed at fec9bdc4). Exact-head re-audit PASS at a638c0f6 against main 1fdc222f: zero blocking findings, 0 PR-caused P1 and 0 unresolved threads.
• Exact head / current base: a638c0f652edcdbdbd629501a0ad5a0be6af6fd8 / 1fdc222fdbc7ee733c05c186f4ba5f62f2839254 (main).
• Production-branch deletion, bypass, or miswire proof: N/A. No production code change. The LiteRT-LM floor is pinned by verify_release_docs_versions --release-prep, and reverting it to >=0.19.0 fails that check.
• Affected-family real-model/artifact evidence: N/A. This PR changes no pin. Runtime evidence for v0.19.1-2 is in #1830 and #1843.
• 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 a638c0f6 / 1fdc222f (tool/testing/high_risk_readiness.dart) is internally consistent and exits 2 (unverifiedPrerequisites / externalPrerequisitesUnavailable). That is the expected local result, not operational readiness. It cites both audits and the affected test test/unit/tooling/verify_release_docs_companion_core_constraint_test.dart ("the checkout constrains every companion to its core minor", against tool/testing/verify_release_docs_versions.dart). That case passes at head and fails under a mutation that sets the core version back to 0.19.0 while keeping the LiteRT-LM floor >=0.19.1.
• Publication: merging into main publishes to pub.dev and needs explicit maintainer approval.

[github-actions]

Chat app preview removed for leehack/llamadart-chat-pr-1844.