fix: FX-34 small leftovers of docs update 10

[tunjayoff]

FX-34: small leftovers found by docs update 10 (#193). One commit per topic, each with tests.

1. Web UI help text for fetch.only_finished (fix(web)). The help text in frontend/src/locales/ui/en.ts and tr.ts no longer names the 2.x /api match lists that P30 removed. It now says that the setting affects the league download, the Overview counts and ssc status. 05-web-ui.md 6.16 and the open list in 03 section 19 are updated.
2. Player export filter reads the stored match list (fix(export)). ExportService.participant_events first reads the match ids that B2 stores for a player follow (follow_events:player:<id> in store.runtime, follow_sync.listed_events), limited to the other filters' scope. It then adds the matches whose stored line-ups name the player. A followed player's matches now export even when their line-ups were not downloaded. Also changed:
   • the follow_sync.py docstring, which said the list is not stored;
   • the export dialog's note (both languages);
   • ssc export --player help;
   • 02 2.7 and 05 6.10.
3. Live service docstrings (docs(live)). cli/commands/watch.py and services/live/supervisor.py no longer name the removed --watch flag or the watcher:<sport> watcher.
4. Sync fallback to leagues.txt (fix(sync)). The design (02 2.7, FX-13) keeps this fallback, so it stays. When the follows table cannot be read (StorageError), the sync still uses ConfigManager.get_leagues() with every season. This used to be a warning; it is now logged as an error that names the cause and the number of leagues used. A context without a store is not an error and stays silent.
5. services/stats.py (refactor(status)). format_size, its only function with a caller, moved into cli/commands/status.py (ssc status --disk), and the module was deleted. Its dead 2.x adapter (league_counts, disk_usage, system_counts, data_summary) was used only by tests, so it moved into tests/test_status_service.py as test helpers. A test checks that the module is gone, and nothing imports it. 02 1.1 is updated.
6. ssc export default file names (fix(cli)). Without --out, a file is now named like an export job's file: the label (the league, the single team or player, or the dataset; -wide for the wide CSV), then the UTC date, then the UTC time where a job's file has the job id. Examples: exports/premier-league_2026-10-09_142530.jsonl and match_details/processed/events-wide_2026-10-09_142530.csv. The folders stay the same. The naming is shared through data_jobs.export_subject / local_export_name. write_legacy_csv takes an optional name; without one it keeps the 2.x name. The CLI golden harness now normalises _<date-time>. Goldens regenerated with UPDATE_GOLDENS=1:
   • tests/characterization/fixtures/cli/headless_csv_export.golden.json
   • tests/characterization/fixtures/cli/lease_refused.golden.json
7. Schedule task options in config show (fix(config)). _task_row now uses the sink options' rule, through a new loader.mask_task_options. The options that a task's run defines in TASK_RUNS (league_id, scope, include_env, older_than) are shown as they are. Every other key keeps its name, and its value is shown as ***. This applies to both ssc config show and the diagnostics bundle. This is the masking concern behind the original finding (fix(redact): host names in the bundle's log tail; sink values in config errors and options [FX-10] #84, plan section 16).

Changelog entry (3.1)

• Fixed: an export filtered by a player also finds the matches in the player follow's stored match list, not only matches with stored line-ups.
• Changed: ssc export without --out names its file like a web export, with the league or dataset and the UTC date and time (exports/premier-league_2026-10-09_142530.jsonl), instead of epoch seconds. The wide CSV in match_details/processed/ is now events-wide_<date>_<time>.csv, no longer all_matches_<epoch>.csv.
• Changed: ssc config show and the diagnostics bundle hide the value of a schedule task option that the task does not define, as they do for sink options.
• Changed: a sync that cannot read the follows table logs an error (it still downloads the leagues of leagues.txt).
• Fixed: the web UI help for "Finished matches only in a league download" no longer names the removed /api match lists.
• Removed: sofascore_scraper/services/stats.py. format_size moved to the ssc status command.

Checks

Run locally, all green:

• full pytest with STORE_SHADOW_CHECK=1
• ruff
• vue-tsc, vitest, eslint
• npm ci && npm run build

No requests to SofaScore were made.