Kaia Counter v0.5.2 — in-house KaiaSpec candidate

Fix:
- Restores button state after reload.
- Issued visitor: own 8-digit number + GOT IT! + disabled/greyed state.
- Unissued visitor: KaiaSpec + GET NUMBER.
- No reset of existing counter/history.
- Existing plugin identity preserved: kaia-counter-test/kaia-counter-test.php
