[leehack]

Summary

• Docs only: state precisely that LiteRT-LM Web generate(prompt) wraps the prompt in one user turn of the bundle's chat template, and why no workaround ships.
• Runtime finding: @litert-lm/[email protected] (and 0.20.0-nightly.20261108) offers Engine.createSession() with applyPromptTemplateInSession, but Session only has runPrefill(string[]) and runDecode(), which resolves one whole reply: no streaming, no stop cause, no per-token cancel. Using it would change generate() streaming semantics, so the conversation route stays. No runtime/Dart behavior change.
• Docs touched: generation guide, backend selection, support matrix note, llamadart-chat-streaming SKILL.md, both changelogs.

Refs #1863 (stays open: runtime-limited), #1874.

Production-readiness scope

• User-facing scope: accurate documentation of the Web generate() contract.
• Supported platforms/paths: LiteRT-LM Web docs; no code change.
• Unsupported or intentionally unavailable paths: raw generate() on LiteRT-LM Web stays templated until @litert-lm/core offers a streaming raw route or template replacement.
• Out of scope / follow-ups: #1863 stays open.

Completeness checklist

• Declared scope is fully implemented, or explicitly reduced above.
• Unsupported combinations: documented as unavailable.
• Docs, support matrix, skill and changelog updated.
• Regression coverage: N/A, docs only (validation_coverage_test, package_skills_test pass).
• Validation registry: N/A, no capability change (a table row was avoided because it would need a mapping).
• Security/privacy: N/A.
• Follow-ups tracked: LiteRT-LM Web generate() wraps the raw prompt in the bundle's user turn #1863.

PR type guidance

• Docs-only PR: no runtime behavior changes. Validated with the markdown test suites in tool/ci/markdown_test_suites.txt; the ./tool/docs/build_site.sh link check could not start its server locally (port in use), so it is left to CI.

Test Plan

• dart format --output=none --set-exit-if-changed .
• dart test -p vm -j 1 on tool/ci/markdown_test_suites.txt (after fixing the validation-coverage failure)
• Remaining lanes: CI. N/A locally: no code changed.

Matrix Evidence

Matrix row	Scope covered	Platform / model / backend	Result	Evidence / notes
docs-site	docs build	-	CI	local build_site.sh server failed to start
root-vm	markdown suites	macOS VM	PASS

Review Notes

• Independent review status: N/A, docs-only.
• CI status / head SHA: pending.

High-risk regression review

• Classification: standard
• Implementation task: N/A
• Independent blocking QA task: N/A

[github-actions]

Chat app preview for a05d460: https://leehack-llamadart-chat-pr-1876.static.hf.space

Space: https://huggingface.co/spaces/leehack/llamadart-chat-pr-1876

[leehack]

Landed on main via batch integration PR #1895 (rebase merge, main ba4e0e1b; tree identical to the audited integration head 5ffd1224).