feat(idaa): stabilize Bulletin Board module and resolve creation crashes

- Fixed 'post_id' missing error in comment creation by mapping to 'post_id_random'.
- Resolved infinite request loop in post view via untrack() optimization.
- Hardened all property accesses with optional chaining to prevent TypeErrors.
- Migrated comment editor to local reactive state for Svelte 5 stability.
- Refactored post visibility layer to use derived reactive filtering.
- Standardized ID mapping patterns across all BB components.

src/lib/ae_posts/db_posts.ts

@@ -120,7 +120,7 @@ export interface Post_Comment {
 export class MySubClassedDexie extends Dexie {
     // We just tell the typing system this is the case
     post!: Table<Post>;
-    post_comment!: Table<Post_Comment>;
+    comment!: Table<Post_Comment>;
 
     constructor() {
         super('ae_posts_db');
@@ -136,7 +136,7 @@ export class MySubClassedDexie extends Dexie {
                 tmp_sort_1, tmp_sort_2,
                 enable, hide, priority, sort, group, notes, created_on, updated_on, [updated_on+created_on], [created_on+updated_on]`,
 
-            post_comment: `
+            comment: `
                 id, post_comment_id,
                 post_id,
                 name,