fix(machine): mobile UI polish and shadcn-vue ScrollArea

- Use h-dvh instead of h-screen for mobile browser viewport
- Add ScrollArea component (shadcn-vue) to replace native scrollbars
- Move Hide Debug into debug bar row, show Show Debug only when off
- Responsive cash-out denomination grid (single col on mobile)
- Add safe-area padding for mobile gesture bar
- Add business model documentation

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docs/business-model.md

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+# Business Model
+
+How we place ATMs at locations and make them sustainable for everyone involved.
+
+## Principles
+
+- **No KYC** — more users, less friction, preserves privacy
+- **Good energy locations** — we seek places with community trust and genuine intent
+- **Bitcoin-native infrastructure** — Lightning, Nostr, Cashu — no legacy payment rails
+- **Operator sovereignty** — locations can choose how much they want to manage themselves
+
+## Deployment Models
+
+### Managed (we run it)
+
+We own the machine and handle all operations. The location provides power, internet, and floor space.
+
+| Aspect              | Details                                   |
+| ------------------- | ----------------------------------------- |
+| Machine ownership   | Us                                        |
+| Liquidity           | Our Lightning channels + cash servicing   |
+| Software updates    | Us (remote via Nostr)                     |
+| Cash management     | Us (periodic servicing visits)            |
+| Fee configuration   | Us                                        |
+| Revenue to location | Fixed monthly hosting fee OR % of tx fees |
+
+Best for locations that want passive income with zero involvement.
+
+### Self-Sovereign (they run it)
+
+The location buys (or finances) the machine and runs their own stack.
+
+| Aspect            | Details                                  |
+| ----------------- | ---------------------------------------- |
+| Machine ownership | Them                                     |
+| Liquidity         | Their own Lightning node + Lightning.Pub |
+| Software updates  | Them (we provide releases)               |
+| Cash management   | Them                                     |
+| Fee configuration | Them                                     |
+| Revenue           | 100% theirs                              |
+
+Best for bitcoiners who want to run infrastructure and keep full control. We provide the software, hardware, and support.
+
+### Machine Financing
+
+For the self-sovereign model, we can offer financing:
+
+- We purchase the machine upfront
+- Location pays it off over time (from ATM revenue)
+- Once paid off, they own it outright
+- We provide support during the financing period
+
+## Revenue Models
+
+### Fixed Hosting Fee
+
+- We pay the location a flat monthly fee for hosting
+- Simpler accounting, predictable income for location
+- We take all transaction fee revenue
+- Works well for locations that just want passive income
+
+### Profit Sharing
+
+- Location receives a % of transaction fees
+- Aligns incentives — they benefit from higher volume
+- More attractive to engaged locations
+- Requires transparent reporting (could be on-chain/Nostr-verifiable)
+
+### Foot Traffic Value
+
+Beyond direct revenue, the ATM provides:
+
+- People visit specifically to use the ATM, then browse/buy at the location
+- Bitcoin-friendly branding signals to the community
+- Conversation starter — draws curious newcomers
+- Community hub potential — meetup anchor point
+
+## Location Criteria
+
+We're selective about where we place machines. The goal is to find locations with **good energy** — places where the community is genuine and the environment discourages misuse.
+
+### Ideal locations
+
+- Coffee shops, cafes, local restaurants
+- Co-working spaces, maker spaces
+- Bitcoin meetup venues, hackerspaces
+- Surf shops, yoga studios, wellness centers
+- Local/independent businesses (not chains)
+- Places where the owner is curious about or already into Bitcoin
+
+### What we look for
+
+- Owner alignment — understands or wants to understand Bitcoin
+- Community trust — regulars know each other, self-policing
+- Foot traffic — enough people to make the machine worthwhile
+- Stable internet + power
+- Visible but not exposed — inside the business, not on the street
+
+### What we avoid
+
+- High-crime areas
+- Anonymous/transient locations (gas stations on highways, etc.)
+- Businesses with no community connection
+- Anywhere the owner is purely financially motivated with no alignment
+
+## Technical Requirements
+
+For the managed model to work at scale, we need:
+
+- **Remote monitoring** — machine status, cash levels, error alerts over [[clink-protocol|CLINK]]/Nostr
+- **Operator dashboard** — manage cassettes, view transactions, update config remotely
+- **Multi-machine support** — one Lightning.Pub instance serving multiple ATMs
+- **Fee configuration** — per-machine fee % set by operator
+- **Availability broadcast** — public Nostr events indicating cash-in/cash-out availability (see [[ndebit-cash-in-flow|cash-in flow]])
+
+## Related
+
+- [[device-configuration]] — hardware setup for different machine models
+- [[machine-installation]] — NixOS installation on ATM hardware
+- [[clink-protocol]] — CLINK protocol for ATM-wallet communication
+- [[ndebit-cash-in-flow]] — cash-in payment flow