## ADDED Requirements

### Requirement: Diagnose missing SMS receiver delivery
The app SHALL explain why `SmsReceiver.onReceive` may not be called when a new SMS arrives.

#### Scenario: SMS permission is missing or unusable
- **WHEN** `RECEIVE_SMS` is not granted or is unusable because of restricted permission behavior
- **THEN** the app MUST report that the system SMS broadcast path is blocked by permission state

#### Scenario: App was force-stopped
- **WHEN** diagnostics indicate the app has not run since a user force-stop or package inactive state
- **THEN** the app MUST report that force-stopped apps are not expected to receive background broadcasts until manually opened

#### Scenario: HyperOS background policy is likely blocking delivery
- **WHEN** SMS appears in the inbox fallback path but no system SMS broadcast was recorded
- **THEN** the app MUST report that HyperOS autostart or battery policy may be blocking receiver delivery
- **AND** it MUST point the user to the background setup checklist

### Requirement: Correlate broadcast and inbox fallback results
The app SHALL record enough source metadata to distinguish SMS broadcast success from inbox fallback success.

#### Scenario: System broadcast receives SMS
- **WHEN** `SmsReceiver` handles `SMS_RECEIVED_ACTION`
- **THEN** the app MUST store the source as `system_sms_broadcast`
- **AND** update the latest broadcast receive timestamp

#### Scenario: Inbox observer sees SMS
- **WHEN** the ContentObserver or manual inbox reader finds a new SMS
- **THEN** the app MUST store an inbox source such as `sms_inbox_observer`, `sms_inbox_manual`, or `sms_inbox_polling`
- **AND** keep it distinct from system broadcast delivery

#### Scenario: Inbox succeeds after broadcast silence
- **WHEN** inbox fallback finds a verification SMS newer than the last recorded broadcast
- **THEN** the app MUST show a diagnostic message that the SMS was present in the inbox but was not delivered through the receiver path

### Requirement: Keep diagnostics local and privacy-minimized
The app SHALL diagnose receiver delivery without unnecessarily retaining full SMS bodies.

#### Scenario: Diagnostic record is saved
- **WHEN** the app stores SMS delivery diagnostics
- **THEN** it MUST store timestamp, source, sender summary, parse status, and failure reason
- **AND** it SHOULD avoid persistent storage of full SMS body unless a debug-only setting is enabled

#### Scenario: Logcat output is produced
- **WHEN** receiver or keepalive code logs diagnostic details
- **THEN** it MUST avoid logging full SMS body by default
- **AND** it MUST make source path and failure reason visible enough for debugging

### Requirement: Validate delivery across target device states
The app SHALL validate SMS receiver delivery under foreground, background, lockscreen, reboot, and force-stop states.

#### Scenario: Background keepalive is enabled
- **WHEN** the app is backgrounded and the keepalive notification is visible
- **THEN** receiving a test SMS MUST either update the latest result through `system_sms_broadcast`
- **OR** report a specific fallback/blocked state

#### Scenario: Device reboots
- **WHEN** the target Xiaomi phone reboots
- **AND** the user previously enabled keepalive and Xiaomi autostart
- **THEN** the app MUST record whether boot restore ran
- **AND** whether the first post-boot SMS reached `SmsReceiver`

#### Scenario: User force-stops the app
- **WHEN** the user force-stops the app from system settings
- **THEN** the app MUST NOT claim reliable SMS delivery until the user manually opens the app again