feat(sync): 运动详情改为同步入库，详情页只读本地

按需回源是错的：点一次运动要等七个 Garmin 接口，网络好的时候慢，
网络差的时候直接超时（实测公网下 Network Error）。

- sync_data 顺带补齐缺详情的运动
- POST /api/garmin/sync-details 后台补齐存量，GET 查进度
- 详情页只读本地库；没有就提示去同步，不再回源
- 同步页新增「补齐运动详情」按钮，带进度

身体年龄：加入公开的阻尼系数
- 34 岁 VO₂max 46 原本算出 21 岁。不是算错，是方法本身会饱和：
  人与人之间的 VO₂max 标准差约 7，而年龄每年只带来约 0.35 的衰减，
  于是稍微能练的人都会撞到参考表最年轻一档。
- 按 50% 向实际年龄收拢，收敛范围 ±20 → ±12 岁，同一算例现在给 27 岁。
- 去掉「高于最年轻一档按 20 岁计」的硬地板，那是一道正好落在用户身上的悬崖。
- 界面同时显示未收拢的原始值，阻尼系数写进评分依据。

路由：为每个路径补无斜杠别名
- F7 写地址栏时去掉尾斜杠，于是 /daily/ 在地址栏是 /daily，
  而那个地址匹配不到任何路由，刷新或分享就落到「找不到页面」。

布局：让页面结构上无法被撑宽
- 网格改用 minmax(min(210px,100%),1fr)：裸的 minmax(210px,1fr) 允许
  两列加起来超过窄屏宽度，第二张卡就被切掉在屏幕外。
- .ring-row 用 minmax(0,1fr)，1fr 会以 min-content 兜底，一句长说明就能
  把整行顶宽。
- .page-inner 加 overflow-x: clip。
- html/body 用 100dvh：手机浏览器把自己的地址栏盖在布局视口上，
  100% 高的应用会把底部 Tab 栏顶到它们下面——对用户来说就是没有 Tab 栏。

测试：新增 122 项（设置 44、身体年龄 44、运动详情 42），全量 446 项通过。

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

backend/services/garmin.py

@@ -24,7 +24,7 @@ import json
 import os
 import threading
 
-from db import execute, query_one
+from db import execute, query_one, query_all
 from config import DB_TYPE
 from services import health
 
@@ -586,28 +586,7 @@ def _build_detail(client, activity_id):
     }
 
 
-def get_activity_detail(user_id, activity_id, creds=None, refresh=False):
-    """Cached detail for one activity, fetched from Garmin on first open."""
-    activity_id = str(activity_id)
-
-    if not refresh:
-        row = query_one(
-            "SELECT payload FROM activity_details "
-            "WHERE user_id = ? AND activity_id = ?",
-            [user_id, activity_id],
-        )
-        if row and row.get("payload"):
-            try:
-                cached = json.loads(row["payload"])
-                cached["cached"] = True
-                return cached
-            except ValueError:
-                # A truncated row is worth refetching, not worth crashing on.
-                pass
-
-    client = _connect(creds or {}, user_id=user_id)
-    detail = _build_detail(client, activity_id)
-
+def _store_detail(user_id, activity_id, detail):
     cols = ["activity_id", "user_id", "payload", "fetched_at"]
     values = [activity_id, user_id, json.dumps(detail, default=str),
               datetime.datetime.utcnow().isoformat(timespec="seconds")]
@@ -622,8 +601,93 @@ def get_activity_detail(user_id, activity_id, creds=None, refresh=False):
                f"({placeholders}) ON CONFLICT(activity_id) DO UPDATE SET {updates}")
     execute(sql, values)
 
-    detail["cached"] = False
-    return detail
+
+def read_activity_detail(user_id, activity_id):
+    """The stored detail for one activity, or None if it was never synced."""
+    row = query_one(
+        "SELECT payload FROM activity_details WHERE user_id = ? AND activity_id = ?",
+        [user_id, str(activity_id)],
+    )
+    if not row or not row.get("payload"):
+        return None
+    try:
+        return json.loads(row["payload"])
+    except ValueError:
+        # A truncated row is worth re-syncing, not worth crashing on.
+        return None
+
+
+def sync_activity_details(client, user_id, limit=None, on_progress=None):
+    """Fetch and store the full detail for activities that lack one.
+
+    Detail used to be fetched when the user opened an activity, which meant
+    seven Garmin calls on the critical path of a tap: slow at best, and a
+    timeout whenever the link was poor. It belongs in the sync, so the screen
+    only ever reads the local database.
+    """
+    rows = query_all(
+        "SELECT a.id FROM activities a "
+        "LEFT JOIN activity_details d ON d.activity_id = a.id "
+        "WHERE a.user_id = ? AND d.activity_id IS NULL "
+        "ORDER BY a.start_time DESC",
+        [user_id],
+    )
+    if limit:
+        rows = rows[:limit]
+
+    stored = 0
+    for i, row in enumerate(rows):
+        try:
+            _store_detail(user_id, row["id"], _build_detail(client, row["id"]))
+            stored += 1
+        except Exception:  # noqa: BLE001 - one bad activity must not stop the rest
+            continue
+        if on_progress:
+            on_progress(i + 1, len(rows))
+    return stored
+
+
+_detail_progress = {}
+
+
+def detail_sync_status(user_id):
+    """Progress of the detail backfill for this account."""
+    return _detail_progress.get(user_id) or {"running": False, "done": 0, "total": 0}
+
+
+def start_detail_sync(user_id, limit=None):
+    """Backfill activity details in the background.
+
+    Each activity costs several Garmin calls, so 170 of them run for minutes —
+    far too long to hold a request open. The UI polls instead.
+    """
+    state = _detail_progress.get(user_id)
+    if state and state.get("running"):
+        return state
+
+    _detail_progress[user_id] = {"running": True, "done": 0, "total": 0, "error": None}
+
+    def run():
+        try:
+            client = _connect({}, user_id=user_id)
+
+            def progress(done, total):
+                _detail_progress[user_id] = {
+                    "running": True, "done": done, "total": total, "error": None,
+                }
+
+            stored = sync_activity_details(client, user_id, limit, on_progress=progress)
+            _detail_progress[user_id] = {
+                "running": False, "done": stored,
+                "total": _detail_progress[user_id].get("total", stored), "error": None,
+            }
+        except Exception as e:  # noqa: BLE001 - reported through the status endpoint
+            _detail_progress[user_id] = {
+                "running": False, "done": 0, "total": 0, "error": describe(e),
+            }
+
+    threading.Thread(target=run, daemon=True, name=f"detail-sync-{user_id}").start()
+    return _detail_progress[user_id]
 
 
 # Above this many days a sync is long enough that the caller must not block
@@ -711,6 +775,14 @@ def sync_data(user_id, creds, days=None, client=None):
     except Exception as e:
         day_errors.append(f"activities: {describe(e)}")
 
+    # Full detail for any activity that does not have it stored yet, so that
+    # opening one later is a local read.
+    details_synced = 0
+    try:
+        details_synced = sync_activity_details(client, user_id)
+    except Exception as e:
+        day_errors.append(f"activity_details: {describe(e)}")
+
     # Badges and personal records are account-wide rather than per-day, so
     # they are fetched once per sync rather than inside the day loop.
     badges_synced = 0
@@ -738,7 +810,8 @@ def sync_data(user_id, creds, days=None, client=None):
         last_error="; ".join(day_errors[:3]) if day_errors else None,
     )
     message = (
-        f"同步完成，更新 {days_synced} 天数据、{activities_synced} 条运动记录、"
+        f"同步完成，更新 {days_synced} 天数据、{activities_synced} 条运动记录"
+        f"（含 {details_synced} 条详情）、"
         f"{badges_synced} 个奖励、{records_synced_pr} 项个人纪录"
     )
     if day_errors: