In-app new user guide

[Adamskiee]

Summary. Onboarding screens exist (features/getting-started, app/getting-started), but a dedicated post-onboarding user guide is not clearly present.

Evidence. getting-started covers first-run onboarding; no separate in-app help/guide surface found.

Recommendation. Clarify scope vs. existing getting-started screens; if distinct, add an accessible in-app user guide. (Overlaps the already-implemented getting-started screens.)

Backlog item 33.

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Filed from docs/issues-to-review.md backlog review.