[Widget] Add call and message launcher entry points

[kalvin807]

Why

The launcher showed a single call CTA and reached text only after opening the widget; starting a call also took two clicks. This makes text a first-class launcher action and lets the call button start a call in one click.

What

• Capability-derived entry points on the expandable launcher (tiny/compact/full):
  • Voice-capable (!text_only) → call ("Start a call", primary).
  • Text-capable (text_input_enabled) → message ("Message"; secondary, or primary when call is absent).
  • Multimodal shows both; voice-only shows call; text-only shows message.
• ⚠️ Call connects directly on click (terms still prompt) and opens the sheet.
• Message opens the sheet focused on the text input; session starts on first send.
• Language picker added to the expandable collapsed trigger; clicking it opens the dropdown without expanding the widget.
• New start_message text key (default "Message").
• Visibility derived via one useTriggerEntryPoints hook.
• Side changes: extract useCallButtonDisabled(); remove a dead min-h-18 class on the chat input.

CleanShot.2026-06-02.at.15.18.12.mp4

Testing

• New ExpandableTriggerActions.test.ts
• Updated index.test.ts / DismissButton.test.ts for the one-click flow.

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Note

Medium Risk
Changes how users start voice vs text sessions and terms-gated flows on the expandable launcher; behavior is covered by new and updated browser tests but affects core embed UX.

Overview
The expandable widget launcher (tiny / compact / full) now shows separate Start a call and Message actions when disconnected, instead of a single chevron that doubled as start/expand. Visibility comes from useTriggerEntryPoints: voice-capable agents get call; text-capable agents get message; multimodal gets both.

Call accepts terms, opens the sheet, and starts the session in one click. Message accepts terms, opens the sheet, and focuses the text input via pendingInputFocus; the conversation still starts on first send in SheetActions. The collapsed chevron is only expand/collapse (or expand mid-call). The language picker stays on the collapsed launcher and no longer expands the widget when opened (stopPropagation on TriggerLanguageSelect). useCallButtonDisabled centralizes connecting/disconnecting disable state. New copy key start_message (default "Message"). Launcher layout uses min-h-11 to avoid height bounce during cross-fades; chat icon SVG updated.

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