Add Strava sync status report and manual trigger to admin panel

Each sync run now writes _strava_sync_status.json per user (status,
imported count, error message). New admin endpoints expose this data
and allow triggering an on-demand sync. The admin page gains a Strava
Sync section showing per-user token/credentials state, total imported,
last sync time, and last-run status with inline error messages.

bincio/sync_strava.py

@@ -20,13 +20,35 @@ from pathlib import Path
 
 import click
 
-_TOKEN_FILE = "strava_token.json"
-_CREDS_FILE = "strava_credentials.json"
-_SYNC_FILE  = "_strava_sync.json"
+_TOKEN_FILE   = "strava_token.json"
+_CREDS_FILE   = "strava_credentials.json"
+_SYNC_FILE    = "_strava_sync.json"
+_STATUS_FILE  = "_strava_sync_status.json"
 
 log = logging.getLogger("bincio.sync_strava")
 
 
+def _write_status(
+    user_dir: Path,
+    status: str,
+    imported: int,
+    errors: int,
+    error_message: str | None = None,
+) -> None:
+    payload: dict = {
+        "status": status,
+        "imported": imported,
+        "errors": errors,
+        "last_run": datetime.now(timezone.utc).isoformat(),
+    }
+    if error_message is not None:
+        payload["error_message"] = error_message
+    try:
+        (user_dir / _STATUS_FILE).write_text(json.dumps(payload, indent=2), encoding="utf-8")
+    except Exception:
+        pass
+
+
 def _load_creds(user_dir: Path) -> tuple[str, str] | None:
     """Return (client_id, client_secret) from strava_credentials.json, or None."""
     p = user_dir / _CREDS_FILE
@@ -59,6 +81,7 @@ def sync_user(user_dir: Path) -> tuple[int, int]:
     creds = _load_creds(user_dir)
     if creds is None:
         log.debug("sync[%s]: no strava_credentials.json — skipped", handle)
+        _write_status(user_dir, "no_credentials", 0, 0)
         return 0, 0
 
     client_id, client_secret = creds
@@ -67,6 +90,7 @@ def sync_user(user_dir: Path) -> tuple[int, int]:
         token = ensure_fresh(user_dir, client_id, client_secret)
     except StravaError as exc:
         log.error("sync[%s]: token refresh failed: %s", handle, exc)
+        _write_status(user_dir, "token_error", 0, 1, str(exc))
         return 0, 1
 
     access_token = token["access_token"]
@@ -89,6 +113,7 @@ def sync_user(user_dir: Path) -> tuple[int, int]:
         all_acts = fetch_activities(access_token, after=after_ts)
     except StravaError as exc:
         log.error("sync[%s]: fetch_activities failed: %s", handle, exc)
+        _write_status(user_dir, "api_error", 0, 1, str(exc))
         return 0, 1
 
     new_acts = [a for a in all_acts if str(a["id"]) not in imported_ids]
@@ -97,6 +122,7 @@ def sync_user(user_dir: Path) -> tuple[int, int]:
         handle, len(new_acts), len(all_acts) - len(new_acts),
     )
     if not new_acts:
+        _write_status(user_dir, "ok", 0, 0)
         return 0, 0
 
     # Load existing index so we can update it in place
@@ -158,6 +184,7 @@ def sync_user(user_dir: Path) -> tuple[int, int]:
     merge_all(user_dir)
 
     log.info("sync[%s]: done — %d imported, %d errors", handle, imported, errors)
+    _write_status(user_dir, "ok", imported, errors)
     return imported, errors