Post-rebase reconciliation of the two TUI lines that evolved in parallel:
- header subtitle prefers the latest logged session title over the configured
welcome; the process-local auto-title owns the whole terminal title while a
logged session/title still wins through the suffixed form
- footer keeps staging's model/cwd/usage/cache layout and gains master's
context-percent segment; per-step usage dedup carries cache buckets
- test harness only stubs the llm catalog when the test did not mount the
real LlmService, and defaults the TUI clock to the real Date.now
- the plugin-shaped /reload test composes commands+llm like the shipped app