feat: universal reorder grip handles and compact UI density

- Add generic move_in_order() to BaseRepository for reorder support
- Add reusable reorder_arrows.html partial with grip dot handles
- Add reorder routes to all 9 list routers (tasks, notes, links, contacts, meetings, decisions, appointments, lists, focus)
- Compact row padding (6px 12px, gap 8px) on .list-row and .focus-item
- Reduce font size to 0.80rem on row titles, sidebar nav, domain tree

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

routers/tasks.py

@@ -481,3 +481,15 @@ async def remove_contact(
         "DELETE FROM contact_tasks WHERE contact_id = :cid AND task_id = :tid"
     ), {"cid": contact_id, "tid": task_id})
     return RedirectResponse(url=f"/tasks/{task_id}?tab=contacts", status_code=303)
+
+
+@router.post("/reorder")
+async def reorder_task(
+    request: Request,
+    item_id: str = Form(...),
+    direction: str = Form(...),
+    db: AsyncSession = Depends(get_db),
+):
+    repo = BaseRepository("tasks", db)
+    await repo.move_in_order(item_id, direction)
+    return RedirectResponse(url=request.headers.get("referer", "/tasks"), status_code=303)