tip: ignore non-object SSE keep-alive frames (#50508)

[kvnloo]

Tip leaf (fork-only) — CLEAN

Maps to work-order issue #154. Upstream origin anomalyco#50508 (not touched / not promoted).

What: Drop empty/[DONE]/non-object JSON keep-alive SSE payloads so decodeChunk sees one object event per element (gateways that inject data: null).

Commit: 8f3d1170c470fa3893a2652075901b5a8c3fab53
Origin tip SHA: 7dd74c0601fd

Proof: fail→pass on openai-compatible-chat keep-alive filters (GREEN 2 / NEG 1 fail / RESTORE 2).

github_writes_origin: 0. Codex promote parked.

[github-actions]

Hey! Your PR title tip: ignore non-object SSE keep-alive frames (#50508) doesn't follow conventional commit format.

Please update it to start with one of:

• feat: or feat(scope): new feature
• fix: or fix(scope): bug fix
• docs: or docs(scope): documentation changes
• chore: or chore(scope): maintenance tasks
• refactor: or refactor(scope): code refactoring
• test: or test(scope): adding or updating tests

Where scope is the package name (e.g., app, desktop, opencode).

See CONTRIBUTING.md for details.

[github-actions]

This PR doesn't fully meet our contributing guidelines and PR template.

What needs to be fixed:

• PR description is missing required template sections. Please use the PR template.

Please edit this PR description to address the above within 2 hours, or it will be automatically closed.

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[kvnloo]

READY_UPSTREAM

Rechecked before promotion:

• upstream PR fix(opencode): ignore non-object SSE keep-alive frames anomalyco/opencode#50508 is open
• current upstream head exactly matches Grok's tested tip: 7dd74c0601fdc1b8f16e2c2b75aa8204cd021d25
• no prior kvnloo validation comment is present
• fail → pass → restore evidence in this fork PR applies to that exact head

Use local gh/Hermes to post the validation note upstream; the ChatGPT GitHub App gets 403 on anomalyco/opencode. Do not open a duplicate PR.