Signal Collector 0.6.1

A MAINTENANCE RELEASE FROM A CODE AUDIT

No new measurement feature. Reliability fixes for collection and export.

DATA INTEGRITY

- If the write falls behind, the number of unwritten samples is shown in the app and recorded in the export header as dropped_samples. Samples used to be discarded without warning.
- A setting outside the allowed range is pulled back into it; a zero interval can no longer spin a scan with no pause.
- The write into the database can no longer lose a sample while the measurement is ending.

COLLECTION RELIABILITY

- The microphone is released only after the read completes, so Stop cannot touch an audio input that is already released.
- With Bluetooth switched off, the sources are not marked as measured and ADAPTER_DISABLED goes into the export.
- The GNSS, location, Wi-Fi RTT and cellular callbacks run off the main thread, so raw GNSS does not slow the controls.

EXPORT

- The format is now SIGNAL_COLLECTOR_TXT_V3. The dropped_samples header was added and the source_timestamp_ns column, which only duplicated elapsed_realtime_ns, is gone.
- Temporary files created for sharing are cleaned up; the cache no longer grows by a whole measurement with every share.
- The database moves to schema version 2 by migration; existing measurements are preserved.

VERIFICATION

Built, with unit tests and lint clean. A measurement on a device against this build is not verified yet; the last functional test on a Pixel 10a ran with version 0.6.0.