Hydration: water intake from the food log, drop the "+вода" button

Intake is what you already log (liquids count via water_pct), so there is
nothing to tap mid-ride and no guessing an amount. At session start JS seeds
the native deficit from the food log — need-so-far for the time of day minus
logged intake — via set_hydration_config(start_deficit_ml); the service then
accrues sweat on top. Removes the +вода button, hydration_drink and water_drink.txt.

frontend/js/db.js

@@ -507,20 +507,6 @@ async function deleteFoodEntry(id) {
   await execute("DELETE FROM food_log WHERE id = ?1", [id]);
 }
 
-// Quick "+вода": log a plain-water drink so the daily water total/bar reflects it. Finds a
-// ~100% water product at runtime (no hardcoded id). The hydration deficit is handled separately
-// (Rust hydration_drink -> native service). Returns true if it could log to the daily total.
-async function logWaterDrink(ml) {
-  const now = new Date();
-  const date = now.toISOString().slice(0, 10);
-  const time = now.toTimeString().slice(0, 5);
-  const rows = await select("SELECT id FROM products WHERE water_pct >= 99 ORDER BY water_pct DESC LIMIT 1");
-  if (!rows.length) return false;
-  await addFoodEntry(date, time, rows[0].id, ml, "вода", null, null);
-  return true;
-}
-window.DB.logWaterDrink = logWaterDrink;
-
 // ---------------------------------------------------------------------------
 // Activity log
 // ---------------------------------------------------------------------------

frontend/js/main.js

@@ -2783,6 +2783,26 @@ let gpsMap = null;
 let gpsTrailLine = null;
 let gpsMarker = null;
 
+// At session start, seed the native hydration deficit from the FOOD LOG: how far behind on water
+// you are for the time of day (need-so-far minus logged intake). During the session the native
+// service adds sweat on top. Intake comes from what you log, not a button.
+async function seedHydrationDeficit() {
+  if (localStorage.getItem("baldav_hydr_on") !== "1") return;
+  try {
+    let target = parseInt(state.profile?.daily_water_ml) || 2000;
+    let now = new Date();
+    let nowMin = now.getHours() * 60 + now.getMinutes();
+    let wakeStart = 7 * 60, wakeEnd = 23 * 60; // assume waking 07:00–23:00
+    let frac = Math.max(0, Math.min(1, (nowMin - wakeStart) / (wakeEnd - wakeStart)));
+    let needSoFar = target * frac;
+    let intake = await DB.getDailyWaterMl(now.toISOString().slice(0, 10));
+    let startDeficit = Math.max(0, Math.min(5000, Math.round(needSoFar - intake)));
+    let alertMl = parseInt(localStorage.getItem("baldav_hydr_alert")) || 600;
+    await window.__TAURI__.core.invoke("set_hydration_config",
+      { enabled: true, alertMl, sweatMlPerHour: 600, reAlertMin: 15, startDeficitMl: startDeficit });
+  } catch (e) { console.error("seedHydration", e); }
+}
+
 async function renderGpsScreen(container) {
   // Check Bluetooth state if BLE device is paired
   let bleAddr = await DB.getProfileValue("ble_device_addr");
@@ -2897,6 +2917,7 @@ async function renderGpsScreen(container) {
         heightCm: parseFloat(state.profile?.height_cm) || 178,
       } : null;
       await GPS.startRecording(type, wkg, hrProfile);
+      seedHydrationDeficit();
       renderScreen("recording");
     }
   };
@@ -4976,21 +4997,6 @@ async function renderRecordingInline(container) {
     darkBtn.onclick = () => toggleDarkMap();
     btnWrap.appendChild(darkBtn);
 
-    // +вода: записать выпитое — гасит отставание (сигнал гидратации замолкает) и идёт в дневной итог.
-    let waterBtn = document.createElement("button");
-    waterBtn.className = "rec-map-btn rec-water-btn";
-    waterBtn.textContent = "💧";
-    waterBtn.title = "Записать воду";
-    waterBtn.onclick = async () => {
-      let ml = parseInt(localStorage.getItem("baldav_hydr_drink")) || 500;
-      try { await window.__TAURI__.core.invoke("hydration_drink", { ml }); } catch (e) { console.error("drink", e); }
-      try { await DB.logWaterDrink(ml); } catch (e) { console.error("logWater", e); }
-      showToast(`+${ml} мл воды`);
-      waterBtn.classList.add("active");
-      setTimeout(() => waterBtn.classList.remove("active"), 800);
-    };
-    btnWrap.appendChild(waterBtn);
-
     // Nogo: mark the current spot impassable while riding (the planner + on-the-fly reroute
     // will avoid it). Shows existing nogo circles too.
     let recNogoLayer = null;
@@ -8203,9 +8209,8 @@ function showProfileModal() {
         <input id="m-hydr-on" type="checkbox" ${localStorage.getItem("baldav_hydr_on") === "1" ? "checked" : ""}>
         Следить за питьём на тренировке
       </label>
-      <div style="font-size:11px;color:#9aa4ae;margin-top:2px">Во время заезда/VR копится потребность в воде (пот). Молчит, пока успеваешь пить; громкий сигнал (канал будильника, пробивает громкость) - только когда отстаёшь. Кнопка «+вода» на записи гасит отставание.</div>
+      <div style="font-size:11px;color:#9aa4ae;margin-top:2px">Во время заезда/VR копится потребность в воде (пот), а выпитое берётся из того, что ты логируешь в баланс (жидкость по water_pct). Молчит, пока успеваешь пить; громкий сигнал (канал будильника, пробивает громкость) - только когда отстаёшь сверх порога.</div>
       <label style="font-size:13px;display:block;margin-top:4px">Сигнал при отставании, мл <input id="m-hydr-alert" type="number" inputmode="numeric" min="100" max="3000" value="${localStorage.getItem("baldav_hydr_alert") || "600"}" style="width:80px"></label>
-      <label style="font-size:13px;display:block">«+вода» за нажатие, мл <input id="m-hydr-drink" type="number" inputmode="numeric" min="50" max="2000" value="${localStorage.getItem("baldav_hydr_drink") || "500"}" style="width:80px"></label>
     </div>`,
   async overlay => {
     let weight = parseFloat(overlay.querySelector("#m-weight").value) || null;
@@ -8225,11 +8230,9 @@ function showProfileModal() {
     await DB.setProfileValue("daily_water_ml", waterNorm);
     let hydrOn = !!overlay.querySelector("#m-hydr-on")?.checked;
     let hydrAlert = Math.min(3000, Math.max(100, parseInt(overlay.querySelector("#m-hydr-alert")?.value) || 600));
-    let hydrDrink = Math.min(2000, Math.max(50, parseInt(overlay.querySelector("#m-hydr-drink")?.value) || 500));
     localStorage.setItem("baldav_hydr_on", hydrOn ? "1" : "0");
     localStorage.setItem("baldav_hydr_alert", String(hydrAlert));
-    localStorage.setItem("baldav_hydr_drink", String(hydrDrink));
-    try { await window.__TAURI__.core.invoke("set_hydration_config", { enabled: hydrOn, alertMl: hydrAlert, sweatMlPerHour: 600, reAlertMin: 15 }); } catch (e) { console.error("hydration cfg", e); }
+    try { await window.__TAURI__.core.invoke("set_hydration_config", { enabled: hydrOn, alertMl: hydrAlert, sweatMlPerHour: 600, reAlertMin: 15, startDeficitMl: 0 }); } catch (e) { console.error("hydration cfg", e); }
 
     state.profile = { ...state.profile,
       weight_kg: weight ? weight : state.profile.weight_kg,