Decision: drop Device Owner (needs a factory reset); phone client blocks via Accessibility Service + overlay + tamper alert

AGENTS.md

@@ -55,6 +55,9 @@ Check these first. Two are missing and will stop you later if ignored.
 
 **Do not start Phase 5 until the Android toolchain question is answered.**
 
+Phase 5 does **not** need Device Owner and does **not** require a factory reset — see
+§13. Any ordinary Android phone works, including one already in use.
+
 ## 3. Users and roles
 
 | User | Can do |
@@ -82,6 +85,9 @@ Check these first. Two are missing and will stop you later if ignored.
 | FR-13 | Alerts via Apprise when a limit is hit or a device goes offline too long. |
 | FR-14 | Fail safe: when a device cannot reach the broker, it keeps its last state. |
 | FR-15 | Audit log: every state change, who made it, and when. |
+| FR-16 | Phone client blocks by **interruption**, not suspension: an Accessibility Service detects a blocked app in the foreground and a full-screen overlay blocks it. No Device Owner, no factory reset. |
+| FR-17 | **Tamper alert.** If the Accessibility Service is disabled, the app is force-stopped, or the overlay permission is revoked, report it to the Control Service immediately and alert Sam. **This is the real enforcement.** |
+| FR-18 | Site filtering on the phone uses a device-local **VpnService**. No router, no Pi-hole. |
 
 ## 5. Screens and UX flow
 
@@ -162,7 +168,7 @@ The Hub interface is frozen in `central_ai_llm_master/docs/ask-contract.md`.
 | Port | Allocate one (suggest **8791**). Record it once chosen. |
 | URL | `webrestrict.lab.audasmedia.com.au` via Caddy on `.35` |
 | Auth | **Separate session login.** |
-| Kids' phone client | **Kotlin**, Android Device Owner |
+| Kids' phone client | **Kotlin**, Android **Accessibility Service + overlay**. NOT Device Owner — see §13. |
 | Kids' computer client | **Python** (`psutil`, `pystray`) |
 
 ## 10. Rules and constraints
@@ -200,9 +206,14 @@ Python client: subscribe to config, apply process blocking, report telemetry, ov
 warning, keep last state.
 *DoD:* a real Windows machine blocks a listed process during a scheduled window.
 
-**Phase 5 — Phone client**
+**Phase 5 — Phone client (no-wipe)**
-Kotlin Device Owner app: suspend listed packages, overlay, status view, telemetry.
+Kotlin app. An **Accessibility Service** detects a blocked app in the foreground; a
-*DoD:* a real Android phone suspends a listed app during a window.
+full-screen overlay blocks it. Usage Access supplies telemetry. A device-local
+**VpnService** filters sites.
+**No Device Owner. No factory reset.** The app installs like any other app and asks
+for Accessibility + overlay permission.
+*DoD:* on a real Android phone, opening a blocked app raises the block overlay, and
+disabling the service raises a tamper alert that reaches Sam.
 
 **Phase 6 — Schedules, blocklists, allowlists**
 Editors in the dashboard. Allowlist honoured during a block.
@@ -244,6 +255,19 @@ Resolved:
 5. **Admin app** is a separate project (`kotlin_phone_app_admin`); it calls this service.
 6. **Chores to unlock time** removed. Not in scope.
 
+**Android client model (decided 2026-10-13):**
+
+**Device Owner is rejected.** It requires a factory reset, and Sam will not wipe the
+kids' phones. The phone client blocks by **interruption** instead:
+
+- An **Accessibility Service** watches the foreground app.
+- A **full-screen overlay** covers any blocked app.
+- **Usage Access** supplies telemetry.
+- A device-local **VpnService** filters sites.
+- **The child can disable it.** That is accepted. The enforcement is the **tamper
+alert** (FR-17), not the overlay.
+- No wipe, no Device Owner, no managed profile.
+
 Remaining:
 1. Pass-through apps during a lock: confirm the list (Spotify, school sites).
 2. Remote shutdown or sleep for a kid's computer, or blocking only?