Web: sticky provider options win over stale thread selection

Before submitting

• I searched existing issues and did not find a duplicate.
• I am describing a concrete problem or use case, not just a vague idea.

Area

apps/web

Problem or use case

Changing Grok reasoning effort (or other provider options) on an existing thread often fails to reach sendTurn because thread-turn options stay sticky and draft options are empty.

Proposed solution

When per-thread draft has no options, fall back to cross-thread sticky provider options for send. Also drop obsolete Grok Early Access badge.

Why this matters

Composer UI shows the new effort but the server still receives the old one — silent lie.

Smallest useful scope

Options-only sticky fallback. Do not let sticky override thread/project selected model.

Alternatives considered

Force users to start a new thread for option changes — works but fights sticky model UX already used elsewhere.

Risks or tradeoffs

Incorrect activeSelection folding can steal the thread model from sticky — fixed scope is options map only.

Examples or references

PR #5426.

Start in apps/web and trace how composer options reach sendTurn, focusing on the folding of thread and cross-thread sticky options. Use PR #5426 as a reference; done means empty per-thread options fall back to sticky provider options without changing the selected model, and the obsolete Grok Early Access badge is removed.