Refactor extra1 to fertilizer_pump in HAL and main logic

- Renamed `extra1` method and related calls to `fertilizer_pump` for clarity and better domain alignment.
- Updated HAL implementation to control `extra2` GPIO for fertilizer pump operations.
- Added build script trigger to refresh `VERGEN_BUILD_TIMESTAMP` on each build.

Software/MainBoard/rust/src/webserver/post_json.rs

@@ -109,9 +109,9 @@ where
     T: Read + Write,
 {
     let mut board = BOARD_ACCESS.get().await.lock().await;
-    board.board_hal.extra1(true).await?;
+    board.board_hal.fertilizer_pump(true).await?;
     embassy_time::Timer::after_millis(1000).await;
-    board.board_hal.extra1(false).await?;
+    board.board_hal.fertilizer_pump(false).await?;
     Ok(None)
 }