fix(cli): hand update completion directly to the TUI - #36455

What

The update preflight now completes inside its live footer instead of writing a receipt into terminal scrollback.

On success, the status line uses the same left-to-right dissolve as update stages, while the longer header dims out, swaps at its dark midpoint, and brightens into the shorter completion phrase:

OpenCode is updating from 0.0.1-old to 0.0.2-new
⠙ Connecting to OpenCode
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 3/3

becomes:

OpenCode updated to 0.0.2-new
✓ Ready
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 3/3

The monogram brightens to the OpenCode accent, the rail settles to a static full-accent state, the result holds briefly, and then the real TUI takes over. No completion line remains in scrollback.

How

• Replaces the open-ended text spring with deterministic 420ms effects: a directional styled-cell dissolve for status changes and a two-phase luminance dissolve for the unequal-length completion header. Both finish predictably before the 480ms stage floor; only spatial rail progress uses a critically damped spring.
• Runs both completion rows on one coordinated transition contract and waits for actual animation completion before the 650ms settled hold.
• Preserves per-character color and bold styling through the wipe, including the muted/bold OpenCode wordmark, accent version, green check, and white Ready state.
• Uses the canonical compact mark from @opencode-ai/tui/logo instead of copying glyph data.
• Uses OpenTUI's explicit live contract at 60fps, then stops liveness during the settled hold. Each animated line is one Yoga <text> renderable with styled spans rather than one layout renderable per character.
• Follows OpenTUI v0.4.3 teardown semantics: pause, await true renderer idle, then destroy. OpenTUI owns split-footer/output restoration before the TUI renderer starts.
• Makes terminal settlement first-wins and idempotent, so success and failure cannot race two independent teardown paths.

Scope

This changes only the fresh-launch version-mismatch preflight introduced in #36448. Existing TUIs reconnecting to a replaced service remain separate work under #36285.

Testing

• bun typecheck in packages/cli
• bun run test in packages/cli (24 pass)
• Push hook: full workspace typecheck (31 packages)
• Real PTY end-to-end with isolated XDG state:
  • started a registered service as 0.0.1-old
  • launched a client as 0.0.2-new
  • verified real service replacement and the coordinated completion animation
  • verified OpenCode attaches at 0.0.2-new
  • verified no success receipt remains in scrollback
• Reviewed lifecycle and animation behavior against local OpenTUI upstream/main / v0.4.3 source and tests

Demo

Real end-to-end service replacement and TUI handoff, captured at 60fps:

Flow

sequenceDiagram
    participant CLI as New OpenCode CLI
    participant Footer as Update preflight
    participant Service as Background service
    participant TUI as OpenCode TUI

    CLI->>Footer: begin(old version → new version)
    CLI->>Service: replace mismatched service
    Footer->>Footer: stage wipes + spring progress
    Service-->>CLI: healthy new endpoint
    CLI->>Footer: finish()
    Footer->>Footer: dissolve header + ✓ Ready
    Footer->>Footer: brighten monogram + settle full rail
    Footer->>Footer: pause → idle → destroy
    CLI->>TUI: attach to new service