Add side panels, task selection, graph animation, and project docs

- Foldable left panel (user profile) and right panel (task details)
- Clicking a task in the list or graph node selects it and shows details
- Both views (task list + graph) always mounted via absolute inset-0 for
  correct canvas dimensions; tabs toggle visibility with opacity
- Graph node selection animation: other nodes repel outward (charge -600),
  then selected node smoothly slides to center (500ms cubic ease-out),
  then charge restores to -120 and graph stabilizes
- Graph re-fits on tab switch and panel resize via ResizeObserver
- Fix UUID string IDs throughout (backend returns UUIDs, not integers)
- Add TaskDetailPanel, UserPanel components
- Add CLAUDE.md project documentation

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/node_modules/d3-time-format/locale/uk-UA.json

@@ -0,0 +1,10 @@
+{
+  "dateTime": "%A, %e %B %Y р. %X",
+  "date": "%d.%m.%Y",
+  "time": "%H:%M:%S",
+  "periods": ["дп", "пп"],
+  "days": ["неділя", "понеділок", "вівторок", "середа", "четвер", "п'ятниця", "субота"],
+  "shortDays": ["нд", "пн", "вт", "ср", "чт", "пт", "сб"],
+  "months": ["січня", "лютого", "березня", "квітня", "травня", "червня", "липня", "серпня", "вересня", "жовтня", "листопада", "грудня"],
+  "shortMonths": ["січ.", "лют.", "бер.", "квіт.", "трав.", "черв.", "лип.", "серп.", "вер.", "жовт.", "лист.", "груд."]
+}