Add platform poster header text settings

STATE.md

@@ -13,7 +13,7 @@ Current runtime is local infrastructure, not the old VPS.
 - Deploy path: push to `gitea/main` -> Gitea webhook -> Coolify -> Docker build/deploy.
 - Coolify + Gitea LXC: `192.168.1.135` (CTID 102).
 - Coolify app UUID: `n6cnr60anmruiwkiey0pukye` (`FN-8 admin`). API token is only in `D:\DEVELOPMENT\.infra.md`; do not copy it into repo docs.
-- Application LXC: `192.168.1.105` (CTID 105, `new-vk-parser`).
+- Application LXC: `192.168.1.105` (CTID 105, `raa-fn8`).
 - Public admin URL: `https://panel.f-n8.ru` (also `https://admin.f-n8.ru` when DNS is current).
 - Coolify repository URL must be reachable from the deployment container; use `http://192.168.1.135:3000/exostring/new_vk_parser.git` or another resolvable Gitea URL, not `http://coolify.lan:3000/...`.
 - Do not deploy this project through `sw.exostring.xyz`, `109.120.156.205`, `/opt/vk-parser`, or manual `systemctl` unless the user explicitly says the old VPS is being restored.
@@ -60,6 +60,7 @@ canonical git repository as FN-8. Code work for both projects must happen in
 - Coolify app UUID: `korokrhpoyqxf0nw2y8vk7lp` (`RAA admin`).
 - Public admin URL: `https://raa.panel.f-n8.ru`.
 - RAA Postgres container: `m9v14hzfh5mk9kelxzcqvhc6`, DB `raa_parser`, user `raa_parser_user`.
+- Docker destination/LXC for both FN-8 and RAA: CTID `105`, hostname `raa-fn8`, IP `192.168.1.105`.
 - Raw Telegram media channel setting: `tg_media_channel_id=-1004312015562` (`VK RAW RAA`).
 - Final Telegram publication chat setting: `tg_poster_chat_id=-1001303630155` (`Red Airsoft | Страйкбол`).
 - VK publication owner: `vk_poster_owner_id=-36860851`, `vk_poster_from_group=true`.
@@ -70,6 +71,9 @@ canonical git repository as FN-8. Code work for both projects must happen in
   `ai-qualifier=false`, `ai-writer=false`, `tg-poster=false`, `vk-poster=false`,
   `site-poster=false`, `tg_poster_enabled=false`, `vk_poster_enabled=false`.
 - Detailed RAA notes live in `RAA.md`.
+- CT `107` (`raa-parser-poster`) was removed on 2026-08-04. CT `104`
+  (`raa-sender`) remains a valid legacy VK reposting app and is not the shared
+  RAA parser/writer/poster app.
 
 ## Important Text Rules
 
@@ -84,6 +88,10 @@ canonical git repository as FN-8. Code work for both projects must happen in
   - optional project-wide common tags first, then `#category #source`
 - Project-wide common tags live in DB setting `publication_common_tags`.
   FN-8 value: `#новости_снаряжения`. RAA value: `#raa_news #страйкбол`.
+- Optional per-platform header/footer settings:
+  `tg_poster_header_text`, `tg_poster_footer_text`,
+  `vk_poster_header_text`, `vk_poster_footer_text`,
+  `max_poster_header_text`, `max_poster_footer_text`.
 - The editor textarea must show only clean editable text.
 - The list preview in `/editor` should show the publication preview, including composed hashtags.
 - `build_publication_text()` in `src/vk_parser_app/text_utils.py` is display/composition helper only. Do not use it before writing `final_text` to DB.