fix(idaa): harden data sync against padStart crashes and fix Archive Content sort

- Hardened object processors in Archives and Posts modules to safely handle null 'sort' values, preventing runtime TypeErrors during data synchronization.
- Fixed inconsistent sorting in Archive Content list by correctly implementing descending order (sort then reverse) and adding a configuration loading guard to the liveQuery.
- Standardized safe data processing patterns in SVELTE_DEXIE_GUIDE.md.
- Performed minor cleanup and visibility logic hardening in Recovery Meetings module.

documentation/SVELTE_DEXIE_GUIDE.md

@@ -92,6 +92,42 @@ export function createLiveQueryStore<T>(query: () => T | Promise<T>) {
 
 The `createLiveQueryStore` function creates a readable store that automatically updates whenever the data in the `friends` table changes. The `$friends` variable in the component will always contain the latest data from the database.
 
+## Safe Data Processing for IndexedDB Sorting
+
+When preparing data for IndexedDB, especially when creating composite sort keys, it is critical to handle `null` or `undefined` values safely to prevent runtime crashes that can interrupt the data synchronization process.
+
+### 1. Safe String Padding
+Attempting to call `.toString()` or `.padStart()` on a `null` or `undefined` value will throw a `TypeError`. This is a common pitfall when processing optional fields like `sort` or `group`.
+
+**Bad Pattern (Crash Risk):**
+```typescript
+// Crashes if obj.sort is null or undefined
+obj.tmp_sort_1 = `${obj.sort.toString().padStart(3, '0')}`;
+obj.tmp_sort_2 = `${obj.sort?.toString().padStart(3, '0') ?? ''}`; // Still risky if chaining is misunderstood
+```
+
+**Good Pattern (Safe):**
+```typescript
+// Safely handle null/undefined by defaulting to 0 or an empty string BEFORE string manipulation
+const sort_val = (obj.sort ?? 0).toString().padStart(3, '0');
+```
+
+### 2. Correct Sorting with Dexie
+Dexie's `sortBy()` method returns a new array sorted by the specified key. It **ignores** previous `reverse()` calls on the collection. To achieve a descending sort, you must sort first and then reverse the resulting array.
+
+**Incorrect (Ascending Sort Result):**
+```typescript
+// .reverse() is ignored by .sortBy()
+let results = await db.table.where('id').equals(id).reverse().sortBy('sort_key');
+```
+
+**Correct (Descending Sort Result):**
+```typescript
+// Sort ascending first, then reverse the array
+let results = await db.table.where('id').equals(id).sortBy('sort_key');
+return results.reverse();
+```
+
 ## Current Data Flow in `ae_journals` Module
 
 The `ae_journals` module currently uses a manual, API-first caching strategy. It does not use Dexie.js's `liveQuery` function for reactivity.
@@ -105,4 +141,4 @@ The `ae_journals` module currently uses a manual, API-first caching strategy. It
 
 ### Future Improvements
 
-The current implementation could be improved by refactoring it to use Dexie.js's `liveQuery` function. This would simplify the code, reduce boilerplate, and improve the reactivity of the application. By using `liveQuery`, the UI would automatically update whenever the data in the IndexedDB database changes, without the need for manual store updates.
+The current implementation could be improved by refactoring it to use Dexie.js's `liveQuery` function. This would simplify the code, reduce boilerplate, and improve the reactivity of the application. By using `liveQuery`, the UI would automatically update whenever the data in the IndexedDB database changes, without the need for manual store updates.