Task: Add a quickstart CLI snippet to the homepage

An external (Gemini) UX review of the redesigned homepage suggested a short terminal quickstart/install command block for fast developer onboarding, directly on the landing page. ORE Studio has no one-line install today (it's a full C++ project built from source via compass build, no packaged installer/curl-pipe-sh script), so the first real step here is deciding what the snippet should actually show – a git clone + build sequence? A pointer to the pre-built downloads from downloads.org? Something else? – before any markup changes land.

• Decide and document what the snippet shows (build-from-source vs. pre-built download vs. both), matching what actually works today – don't ship a snippet implying an install path that doesn't exist.
• A styled code block on the homepage (matching the site's existing syntax-highlighted pre.src styling) with the chosen command(s).
• Verify the shown command(s) actually work against a fresh checkout.

(Implementation strategy. Written when work starts; key decisions are distilled into the parent story's * Decisions at close, but the plan itself stays — it is the historical record of what we did.)

Manual QA scenarios (scaffolded via compass add test_scenario, run through the QA Validation Runner panel) that verify this task. Link new ones here as they're created; the scenario doc itself links back via its "Verifies task" field.