Update positioning guidance + safety disclaimer

ANDROID_MVP_SPEC.md

@@ -21,7 +21,7 @@ This is a prototype for safe, reliable core experience. It is **not** a medical
 ### 2.1 Goals
 The MVP must prove that Android can reliably:
 1. present required safety information before use,
-2. guide the user through headphone + holder setup,
+2. guide the user through headphone setup and safe positioning,
 3. let the user choose a built-in preset,
 4. run a timed session with synchronized visual + audio output,
 5. handle pause, resume, stop, completion, and interruptions safely,
@@ -87,14 +87,14 @@ To make MVP implementation-ready, the following are fixed decisions:
 7. Interruption / Headphone Warning Sheet
 8. Session Complete
 9. Settings
-10. Holder Guidance
+10. Positioning Guidance
 11. About / Disclaimer (can live inside Settings)
 
 ### 3.2 Navigation Model
 - Root stack navigation
 - Default landing after first-run completion: **Home**
 - Main forward path: `Welcome -> Safety -> Home -> Setup -> Active Session -> Complete`
-- Settings and Holder Guidance reachable from Home and Setup
+- Settings and Positioning Guidance reachable from Home and Setup
 - During Active Session, user should not navigate elsewhere except via pause/stop/OS interruption handling
 
 ### 3.3 Back Navigation Rules
@@ -103,7 +103,7 @@ To make MVP implementation-ready, the following are fixed decisions:
 - Setup: Back returns to Home
 - Active Session: system back disabled or mapped to Pause sheet; must not silently exit session
 - Complete: Back returns Home
-- Settings/Holder Guidance: Back returns to prior screen
+- Settings/Positioning Guidance: Back returns to prior screen
 
 ---
 
@@ -189,7 +189,7 @@ User can modify:
 - countdown preference (Off/5/10)
 - default mode preference (Audiovisual, Audio, Visual)
 - keep screen on during session (default on, locked on for session regardless)
-- show holder guidance before every session (default off)
+- show positioning guidance before every session (default off)
 - theme behavior if needed (dark only for MVP preferred)
 - about/disclaimer access
 
@@ -224,6 +224,9 @@ Purpose: mandatory risk disclosure.
 Required warnings:
 - flashing lights may be unsafe for people with epilepsy, seizure sensitivity, or migraine triggers
 - do not use while driving, walking, cycling, or operating machinery
+- use at your own risk; this app provides no medical advice
+- for immersive visual sessions, keep your eyes closed; do not stare at the screen
+- do not place the phone directly on your eyes; avoid pressure on face/eyes and ensure comfortable breathing/airflow
 - stop immediately if discomfort, dizziness, headache, nausea, anxiety, or eye strain occurs
 - binaural mode requires stereo headphones
 - app is not a medical device
@@ -232,7 +235,7 @@ Components:
 - scrollable warning text
 - acknowledgment checkbox: “I understand the risks and will stop if I feel discomfort.”
 - primary button: I Understand
-- secondary link: Holder Guidance
+- secondary link: Positioning Guidance
 
 Behavior:
 - primary button disabled until checkbox checked
@@ -247,7 +250,7 @@ Purpose: launch point for returning users.
 
 Components:
 - top app bar: title + Settings
-- optional info action: Holder Guidance
+- optional info action: Positioning Guidance
 - three preset cards: Relax, Focus, Sleep Prep
 - each card shows duration, pattern type, beat frequency summary, short description
 - optional footer disclaimer: not medical / use safely
@@ -277,7 +280,7 @@ Components:
 - audio mode section
 - headphone status row
 - brightness recommendation row
-- holder guidance link
+- positioning guidance link
 - Start button
 
 Layout and reachability:
@@ -309,7 +312,7 @@ Behavior:
 - Start disabled if invalid config or no selected mode
 - if selected mode includes audio and no headset detected, show blocking warning and CTA: Continue as Visual
 - brightness row is advisory text, not a system-permission flow
-- optional “Show holder guidance” interstitial before countdown if setting enabled
+- optional “Show positioning guidance” interstitial before countdown if setting enabled
 - helper text for flash interval must explain that lower ms = faster flashing and higher ms = slower flashing
 - Setup must preserve access to all controls when the device rotates between portrait and landscape
 - scrolling behavior must keep validation messages, helper text, and the Start action discoverable rather than hidden below a clipped layout
@@ -328,11 +331,14 @@ States:
 - blocked by missing headphones
 - loading not needed beyond quick preset load
 
-## 5.5 Holder Guidance
+## 5.5 Positioning Guidance
 Purpose: give practical safe setup help.
 
 Content blocks:
-- use a simple cardboard visor/holder
+- lie on your back in a safe, comfortable place
+- rest the phone across the upper nose/forehead area so it stays stable
+- keep your eyes closed during immersive visual sessions
+- stop immediately if you feel discomfort
 - keep phone stable and hands-free
 - do not press device against eyes/face
 - allow airflow and comfort
@@ -440,7 +446,7 @@ Behavior:
 MVP contents:
 - countdown preference
 - default session mode
-- show holder guidance before session
+- show positioning guidance before session
 - re-open safety information
 - about/disclaimer
 
@@ -622,7 +628,7 @@ If crash reporting or analytics is later added, it must be explicitly reviewed a
 - Android native app
 - first-run intro + mandatory safety acknowledgment
 - built-in presets: Relax, Focus, Sleep Prep
-- Home, Setup, Active Session, Completion, Settings, Holder Guidance
+- Home, Setup, Active Session, Completion, Settings, Positioning Guidance
 - audio+visual synchronized session engine
 - pause/resume/stop
 - countdown
@@ -674,7 +680,7 @@ Decision: any significant interruption forces immediate pause and explicit resum
 
 ### 11.6 User Comfort / Holder Confusion
 Risk: uncomfortable or unsafe placement.
-Decision: ship concise holder guidance accessible in onboarding and setup; no printable template in MVP.
+Decision: ship concise positioning guidance accessible in onboarding and setup; no holder required; no printable template in MVP.
 
 ### 11.7 Scope Creep
 Risk: custom sessions and advanced patterns delay MVP.
@@ -793,7 +799,7 @@ Use concise, plain copy. Avoid wellness hype and all medical claims.
 ## 15. Handoff for Andy
 
 ### Explicit Implementation Checklist
-- [ ] Build Android-only MVP with screens: Welcome, Safety, Home, Setup, Active Session, Completion, Settings, Holder Guidance
+- [ ] Build Android-only MVP with screens: Welcome, Safety, Home, Setup, Active Session, Completion, Settings, Positioning Guidance
 - [ ] Implement bundled presets: Relax, Focus, Sleep Prep with defaults from this spec
 - [ ] Persist safety acknowledgment version, settings, last preset, and repeat-session config locally
 - [ ] Implement preflight validation for mode selection, parameter ranges, and headphone route