[Feature] Allow customizing or simplifying thinking status verbs

Feature Request

The thinking status indicator cycles through verbs like "Wandering", "Synthesizing", "Reflecting", etc. while Claude is processing. These feel distracting and unnecessary — a simple "Thinking..." would be clearer and less noisy.

Proposed Solution

Either:

1. Add a setting (e.g. thinkingIndicator: "simple") that replaces all the creative verbs with a plain "Thinking..." message
2. Or just default to "Thinking..." — the rotating verbs don't convey meaningful information about what Claude is actually doing

Why

The current verbs add visual noise without adding information. "Synthesizing" vs "Wandering" vs "Reflecting" don't map to any real difference in what the model is doing — they're cosmetic. For users who spend hours in Claude Code daily, a calm "Thinking..." is preferable to a rotating carousel of verbs.

Additional Context

• Searched existing issues — no prior request for this specific change
• Related: #42090 (status indicator consistency on Opus, closed as stale) — different ask but same area