feat: refresh material names in background every two days

capabilities/am516-delivery-prediction/docs/acceptance_samples.md

@@ -29,6 +29,8 @@ Expected:
 - each usable model includes `缺料物料明细` listing only shortage names, preserving order and deduplicating names; use the API's `物料名称` / `缺料物料名称` first, then resolve `缺料物料` through `data/material_names.json`; the same behavior applies to continuation replies;
 - code-only shortage records with cached names display those names without calling Kingdee; unresolved codes and missing/invalid caches are reported explicitly without displaying codes or inferring names; an empty shortage list says `API未返回缺料记录`, and missing shortage data or invalid BOM keeps the unavailable-data reminder;
 - the cache is Git-trackable, contains only code/name mappings and source metadata, and works in another checkout without the source computer's paths or ERP credentials; refreshes with empty, invalid or conflicting data preserve the previous cache;
+- the native background refresher queries ERP only when at least 48 hours have elapsed since the last successful refresh; unchanged dictionaries do not rewrite the Git cache, added/renamed names are merged, and failed refreshes preserve the cache and last-success state;
+- running the updater on another computer uses that computer's local read-only ERP credentials, never Git-synchronized credentials; the bot sees valid cache changes on its next lookup without a restart;
 - reducer shortages are the sole exception: when `缺料物料` starts with `20.30.`, output only the reducer code, inventory, inspection, in-transit, existing-demand quantities, and in-transit coverage conclusion in the Skill-defined order;
 - shortage items outside the `20.30.` reducer prefix never expose their material codes or quantity details;
 - result is marked as internal candidate;