fix(tui): restore fork branding and layout

[shuv1337]

What changed

• restore the Shuvcode wordmark as the default TUI splash under the new upstream plugin bootstrap
• port the fork's narrow-terminal prompt, logo, footer, and metadata behavior onto the current TUI architecture
• document the channel-specific service files and the V1-to-V2 plugin migration rule

Root cause

The upstream V2 TUI plugin-runtime sync preserved the fork logo assets but orphaned the legacy HomeLogo registration, causing the upstream OpenCode fallback to render. The same sync also dropped three fork responsive-layout patches.

The missing Anthropic subscription login was a separate deployment migration issue: the shared canonical configuration remained V1-shaped, so replacing only its singular plugin field with plural plugins caused those entries to be ignored. The live configuration has been corrected to use the V2 adapters through the V1 migration field.

Validation

• 256 TUI tests passed, 1 skipped
• TUI typecheck passed
• repository push hook passed all 32 package typechecks
• compiled CLI service smoke passed
• oxlint completed with zero errors
• live shuvdev Anthropic integration now advertises Claude Pro/Max OAuth