[leehack]

Summary

Prepares llamadart and the three Apple runtime companions at 0.19.5 for release plan #1899. Merging into main publishes core 0.19.5, then the three companions; it needs the maintainer's explicit go-ahead. Draft: not for merge, tag or publish until the maintainer says so.

Base: main 22134b398.

Production-readiness scope

• User-facing scope: release metadata and docs. Runtime pins since 0.19.4: native LiteRT-LM v0.19.1-2 -> v0.19.1-3 (#1913); llama.cpp v0.9.0 (Web upstream v0.9.0@cd959bae), stable-diffusion v0.3.0-3, Web bridge v0.1.83 and Web LiteRT-LM @litert-lm/[email protected] unchanged.
• Changelogs (core and docs): ## Unreleased becomes ## 0.19.5, compacted from 9 bullets to 8, plus the WebGPU baseline line: #1907 and #1909 (LiteRT-LM strict responseFormat) merged into one; the Metal bullet now says "Adopt native LiteRT-LM v0.19.1-3". #1906 and #1908 (Qwen3-Coder / Seed-OSS parity) stay two bullets, one per template family, both #1898. The bridge bullet says v0.1.83 (unchanged from 0.19.4); the runtime-baseline paragraph carries LiteRT-LM v0.19.1-3. Released sections untouched (patch release: no docs-changelog trim; docs page keeps 0.19.x and 0.18.x).
• Companions:
  • llamadart_litert_lm_flutter 0.19.4 -> 0.19.5: Package.swift pins leehack/[email protected], which core 0.19.1 to 0.19.4 hooks reject, so its core constraint moves >=0.19.1 <0.20.0 -> >=0.19.5 <0.20.0 (required by verify_release_docs_versions --release-prep; published constraints are immutable). Its Unreleased note became ## 0.19.5.
  • llamadart_llama_cpp_flutter and llamadart_stable_diffusion_flutter 0.19.4 -> 0.19.5: no pin change, README install snippets name core ^0.19.5 (release-workflow.md section 2), as in 0.19.4. Constraints stay >=0.19.0 <0.20.0.
  • Published older companions (0.19.0 to 0.19.4) keep their native pins; both pairing directions checked from full tag history by --release-prep.
• Supported platforms/paths / unsupported paths: unchanged by this PR.
• Out of scope / follow-ups: genkit_llamadart and llamadart_model_store untouched; MIGRATION.md unchanged (no breaking change).

Completeness checklist

• Declared scope is implemented.
• Unsupported combinations: N/A, no code change.
• README, installation docs, companion READMEs and all five changelogs updated.
• Regression coverage: release gates pass; pub.dev size guard passes (CHANGELOG.md 137,768 bytes, 52.6% of 262,144).
• Validation coverage registry: N/A (no capability change in this PR).
• Security review: no secrets, tokens or signed URLs.
• Follow-ups: None.

PR type guidance

• Release preparation: versions, install snippets, lockfiles, changelogs and the LiteRT-LM companion's core constraint. No .gitattributes change; changelog union merge was turned off in .git/info/attributes while preparing.
• Feature PR / Bugfix PR / Docs-only PR: N/A.

Test Plan

Pinned Flutter 3.47.1, isolated TMPDIR. The local clone is shallow with a stale unreachable shallow entry, so gates that read tag history ran in a full-history clone at this head's tree.

• dart run tool/prepare_workspace.dart: locks regenerated through pub only (example/chat_app, packages/llamadart_validation, website/examples/observability: local core/companion 0.19.4 -> 0.19.5 only).
• dart format --output=none --set-exit-if-changed .: 0 changed.
• dart analyze: no issues.
• dart test -p vm test/unit/tooling/: 1,717 pass, 6 fail, all in windows_registry_qualification_test.dart (ProcessException: no pwsh on this macOS host; pre-existing, same as Prepare 0.19.4 release #1897).
• dart test -p vm -j 1 --exclude-tags local-only: 14,023 pass, 6 fail, the same six pwsh failures in windows_registry_qualification_test.dart (no pwsh on this macOS host); CI runs the full lane.
• dart test -p chrome --exclude-tags local-only: N/A locally, no lib/ or Web change; CI runs it.
• coverage-lib: N/A, no lib/ change.
• Other checks:
  • verify_release_docs_versions.dart and --release-prep (full-history clone): both exit 0 ("Release docs versions verified: llamadart 0.19.5, llamadart_llama_cpp_flutter 0.19.5, llamadart_litert_lm_flutter 0.19.5, llamadart_stable_diffusion_flutter 0.19.5; checkout llamadart-native v0.9.0."). Before the constraint bump, --release-prep failed for LiteRT-LM companion vs published cores 0.19.1 to 0.19.4.
  • check_webgpu_bridge_tag.dart: OK. companion_pub_preflight.dart: OK for all three companions.
  • check_core_archive.py: pass, 1,930 files staged.
  • ./tool/docs/build_site.sh --port 18095: OK, no broken links.
  • Classifier (origin/main...HEAD): high-risk (artifactConsumer; not releaseAutomation: no workflow or tool change).

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	First audit at 29b846e0: BLOCK on two wording errors (the Seed-OSS \n42\n escape and the #174 bullet). Both fixed in 93410b09. Delta re-audit PASS at 93410b09 against main 22134b39: both verifier modes, mutation controls and rendering checked, evaluator exit 2. Evidence: llamadart-evidence/pr-1917/
release-metadata-verification	versions, constraints, changelog promotion	macOS host, full-history clone	PASS	verify_release_docs_versions --release-prep exits 0.
release-doc-version-consistency	current install docs, companion bumps	macOS host	PASS	verifier, both modes, exit 0.
release-companion-pub-gate	companion pub.dev availability and constraints	macOS host	PASS (pre-merge)	companion_pub_preflight.dart OK; 0.19.5 companions are published by release_on_prep_merge.yml after merge.
genkit-release, android-release-device-pool, release-representative-smokes	N/A	N/A	N/A	Genkit untouched; no Android or runtime-code change in this PR; smokes belong to the publish step.

Review Notes

• Independent review status: PASS at 93410b09 (fresh auditor session, 0 P1/P2).
• CI status / head SHA: 29b846e0f83e2e23c51847b876a0c9c091c86d5a green (CI run; 35 pass, 10 skipped, no rerun)

High-risk regression review

• Classification: high-risk (artifactConsumer).
• Implementation task: 0.19.5 release prep, branch release/prep-0.19.5.
• Independent blocking QA task: PASS at 93410b09. Maintainer approved the merge and publish ("Merge and publish").
• Exact head / current base: 29b846e0f83e2e23c51847b876a0c9c091c86d5a / 22134b3985 (main).
• Production-branch deletion, bypass, or miswire proof: N/A, no production code change.
• Affected-family real-model/artifact evidence: N/A, the LiteRT-LM pin bump was audited and merged in Drop the unused LiteRT-LM Metal accelerator from Apple bundles #1913.
• Explicit unavailable-family or other N/A evidence: N/A.
• Known PR-caused P1 regressions: 0
• Unresolved review threads: 0

[github-actions]

Chat app preview removed for leehack/llamadart-chat-pr-1917.