Mobile activity card: move step meta lines into a Meta tab

Status#

In the mobile app's expanded activity card ("ran code" expandable), each round currently renders like:

Round 2
LLM - openai/gpt-5.5-terra | 61.6s | 1061 tok
Script | Approvals | Result

The LLM meta line (and the CODE · 3.2s line above the tab bar) take up vertical space. Move that info into a new trailing Meta tab:

Round 2
Script | Approvals | Result | Meta

Meta is the last tab and is always offered — which means the tab bar now always renders (it used to hide when Script was the only tab). That's the point: the tab bar replaces the meta lines as the round's compact header.
The code · 3.2s · failed label above the tab bar moves into Meta too — same category of noise the ask is about.
Meta tab body: one line per step, same faint uppercase style as before:
- llm · openai/gpt-5.5-terra · 61.6s · 1061 tok (plus failed/cancelled suffixes as today)
- code · 3.2s · failed
LlmStepView keeps rendering thinking text / streamed response / error — only its meta label line moves. While the llm step is streaming (no code step yet, so no tabs exist), the meta label stays where it is as a fallback; once the round has a code step, the label lives in Meta only.

Add meta to the tab union + tabs array in CodeStepTabs (apps/mobile/src/components/activity-card.tsx) "meta" as const appended unconditionally; tab bar now renders unconditionally since tabs.length ≥ 2 always
Render Meta tab body with llm + code meta lines; pass the round's llm step into CodeStepTabs new llm prop; label strings extracted to llmMetaLabel/codeMetaLabel shared with the streaming fallback
Drop the code · … label above the tab bar; drop the llm meta label from LlmStepView when the round has a code step LlmStepView renders the label only when code === null (streaming, or code half missing)
typecheck / lint / test for apps/mobile tsc clean, oxlint clean, 83 tests pass, knip clean

Single-file change: apps/mobile/src/components/activity-card.tsx.
No component render tests exist for this card (mobile tests are lib-level); behavior change is presentational, so no new tests added.