Docs: clarify Quick Start install fallback options and add-wizard vs add

[Copilot]

First-time users following the Quick Start guide couldn't tell that the curl-script/gh auth login options were fallback-only troubleshooting paths, and the distinction between gh aw add-wizard and gh aw add was buried in prose, making it hard to notice both commands exist.

Tip box: fallback options

• Reworded the Step 1 install Tip box to explicitly state it's a fallback path, self-contained even when the box is skimmed in isolation:

> [!TIP]
> **Fallback options only — skip this unless the command above fails.** If you are encountering authentication issues, use this script instead:

add-wizard vs add: up-front comparison

• Added a short comparison table at the top of Step 2, ahead of the existing prose explanation, so both commands are visible immediately:

Command	Use it when
gh aw add-wizard	Guided, interactive prompts for engine/auth/secrets (used in this guide)
gh aw add	Non-interactive, e.g. scripts or CI

The CLI Commands reference page already had an equivalent comparison table, so no changes were needed there.

• Fixes [deep-report] Clarify Quick Start install fallback options and add-wizard vs add naming for first-time users #55966

[github-actions]

Triage update: Category: docs | Risk: low | Score: 28/100 (impact 10 + urgency 6 + quality 12) | Action: defer | Batch: workflow-runtime

Generated by 🔧 PR Triage Agent · copilot · mai10 · 17.1 AIC · ⌖ 2.78 AIC · ⊞ 15.6K · ◷

[github-actions]

Triage update: Category: docs | Risk: low | Score: 28/100 (impact 10 + urgency 6 + quality 12) | Action: defer | Batch: workflow-runtime

Generated by 🔧 PR Triage Agent · copilot · mai10 · 17.1 AIC · ⌖ 2.78 AIC · ⊞ 15.6K · ◷