feat: add backup CLI commands, AI correction/modifier services, and timezone-aware date display

- Add `devplace backups` CLI subcommands (list, run, prune, clear) with job enqueueing and orphan cleanup
- Introduce `BACKUPS_DIR` and `BACKUP_STAGING_DIR` config paths for backup storage
- Implement `schedule_correction` and `schedule_modification` calls in content creation, comment creation, and comment editing flows
- Add `DEFAULT_CORRECTION_PROMPT` and `DEFAULT_MODIFIER_PROMPT` config constants for AI content processing
- Document timezone-aware date display using `local_dt`/`dt_ago` Jinja globals with client-side `Intl` localization
- Update README with AI content correction/modifier support in direct messages via `@ai` inline instructions
- Add `track_action(user["uid"], "vote")` call on upvote in `apply_vote`

devplacepy/routers/docs/pages.py

@@ -81,6 +81,24 @@ DOCS_PAGES = [
         "kind": "prose",
         "section": SECTION_GENERAL,
     },
+    {
+        "slug": "timezones",
+        "title": "Timezone-aware dates",
+        "kind": "prose",
+        "section": SECTION_GENERAL,
+    },
+    {
+        "slug": "ai-correction",
+        "title": "AI content correction",
+        "kind": "prose",
+        "section": SECTION_GENERAL,
+    },
+    {
+        "slug": "ai-modifier",
+        "title": "AI modifier",
+        "kind": "prose",
+        "section": SECTION_GENERAL,
+    },
     # Tools - public developer tools (everyone)
     {
         "slug": "tools-seo",
@@ -304,6 +322,20 @@ DOCS_PAGES = [
         "admin": True,
         "section": SECTION_ADMIN,
     },
+    {
+        "slug": "backups",
+        "title": "Backups",
+        "kind": "prose",
+        "admin": True,
+        "section": SECTION_ADMIN,
+    },
+    {
+        "slug": "gamification",
+        "title": "Gamification and badges",
+        "kind": "prose",
+        "admin": True,
+        "section": SECTION_ADMIN,
+    },
     # Devii internals - technical reference for the Devii assistant (admins only)
     {
         "slug": "audit-log",