chore: drop the stale NEXT_PUBLIC_GOOGLE_MAPS_API_KEY docs

[Aymericr]

NEXT_PUBLIC_GOOGLE_MAPS_API_KEY is documented in two places and read by none.

$ grep -rn "GOOGLE_MAPS" apps packages --include='*.ts' --include='*.tsx'
(no matches)

The only references are SETUP.md:26 and .env.example:4, and there's no geocoder anywhere in the tree — no Nominatim, Mapbox, Geoapify or Places call — so the "address search" the variable promises doesn't exist in this app. Setting it does nothing.

Docs that advertise a non-existent knob cost real time: someone provisions a Google Cloud key, sets it, sees no address search, and goes looking for the bug in their setup.

Noticed while reviewing #268, where I said I'd clean it up separately.

Docs only — no code changes.

🤖 Generated with Claude Code

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Note

Low Risk
Documentation-only change with no runtime, config, or security impact.

Overview
Removes documentation only for NEXT_PUBLIC_GOOGLE_MAPS_API_KEY, which is not read anywhere in the app and does not enable address search.

.env.example no longer lists the commented Google Maps key block. SETUP.md drops the variable from the optional env table so setup docs match what the editor actually uses (PORT remains the only documented optional var).

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