fix(teacher): group day slots by real lesson start time

slotIndex is a per-department index of non-empty intervals, not a time.
Merging all departments of a period by slotIndex and deriving the slot
time from the first inserted lesson produced shifted times (e.g. Meltsov
10:00 shown at 11:45) depending on sync order. Group by lesson start
minute instead so each department's real times are kept.

Add debug logging for teacher schedule sync/build and debounce teacher
search in picker.

app/src/main/java/agzam/vyatsu/data/remote/TeacherScheduleParser.kt

@@ -5,6 +5,7 @@ import agzam.vyatsu.domain.model.Day
 import agzam.vyatsu.domain.model.Lesson
 import agzam.vyatsu.domain.model.LessonType
 import agzam.vyatsu.domain.model.TimeSlot
+import android.util.Log
 import org.jsoup.Jsoup
 import org.jsoup.nodes.Element
 import java.time.LocalDate
@@ -13,6 +14,7 @@ import java.time.format.DateTimeFormatter
 
 object TeacherScheduleParser {
 
+    private const val TAG = "TeacherParserDebug"
     private val DAY_REGEX = Regex("""^(понедельник|вторник|среда|четверг|пятница|суббота|воскресенье)\s+(\d{2}\.\d{2}\.\d{2})$""")
     private val INTERVAL_REGEX = Regex("""^(\d{2}:\d{2})-(\d{2}:\d{2})$""")
     private val GROUP_TOKEN = Regex("""(?<![\p{L}\p{N}])[А-ЯЁа-яё]{1,4}-\d{2,4}-\d{2}-\d{2}(?![\p{L}\p{N}])""")
@@ -60,6 +62,21 @@ object TeacherScheduleParser {
             }
         }
         flushDay()
+        Log.d(TAG, "parse: teachers=$teachers days=${days.size}")
+        for (day in days) {
+            Log.d(TAG, "  parse ${day.date}: intervals=${day.intervals.size}")
+            for (slot in day.intervals) {
+                val mel = slot.lessons.filter { it.teacher == "Мельцов В.Ю." }
+                val teachersInSlot = slot.lessons.map { it.teacher }.distinct()
+                Log.d(
+                    TAG,
+                    "    slot ${slot.start}-${slot.end} total=${slot.lessons.size} meltsov=${mel.size} teachers=$teachersInSlot"
+                )
+                mel.forEach { l ->
+                    Log.d(TAG, "      mel: room=${l.room} group=${l.group} subj=${l.subject} type=${l.type} raw=${l.raw}")
+                }
+            }
+        }
         return ParsedTeacherSchedule(teachers, days)
     }