Polish: README, AI disclosure, scoped Hellion ImGui style

Replace the inherited upstream README with a Hellion-specific one
that lists the privacy/retention/cleanup/export features, links to
upstream and the relevant unanswered filtering issues, documents
the EUPL-1.2 license relationship, and acknowledges Infi & Anna for
the Chat 2 engine that everything builds on.

Add AI_DISCLOSURE.md with the goatcorp Pair classification, an
explicit list of what AI is and is not used for in this fork
(translations, visual assets and license-sensitive boundaries are
handled by the maintainer), and the tooling list. Drops in before
v0.1 so it's already in place when the repo goes public.

HellionStyle.Push() returns a disposable bundle of ImGui color
pushes (cyan-teal accents on a deep-slate frame with steel
borders) and pops them in reverse on Dispose. Privacy tab and the
first-run wizard wrap their Draw with `using var _style =
HellionStyle.Push()` so only Hellion-owned surfaces get the
HUD-flavored palette while upstream Chat 2 tabs render in their
original style — important so cherry-picks from upstream don't
fight with our color overrides.

README.md

@@ -1,34 +1,91 @@
-# Chat 2
-#### Electric Boogaloo - ♪ A whole new chat, a new fantastic chat window ♪
+# Hellion Chat
 
-Chat 2 is a complete rewrite of the in-game chat window as a plugin.
-It supports:
+A GDPR-compliant, Linux-aware fork of [Chat 2](https://github.com/Infiziert90/ChatTwo)
+for FINAL FANTASY XIV / Dalamud.
 
-- Unlimited tabs
-- Tabs that always send to a certain channel
-- More flexible filtering
-- RGB channel colouring
-- Completely variable font size
-- Sidebar tabs
-- Unread counts
-- Emotes
-- Screenshot mode (obfuscate names)
+Same chat replacement you know from upstream, with extra controls for what
+actually gets stored:
 
----
+- **Channel whitelist** for database persistence (GDPR Art. 25 — privacy by
+  default). Out-of-the-box only your own conversations are kept: Tells, Party,
+  Free Company, Linkshells, Cross-World Linkshells, Alliance, ExtraChat. Public
+  chat from strangers (Say/Shout/Yell), Novice Network, NPC dialogue, system
+  spam and battle messages stay outside the database unless you opt them in.
+- **Per-channel retention** with a 24-hour idempotent background sweep. Tells
+  default to 365 days, own-conversation channels to 90, the global default to
+  30. Off until you switch it on — the plugin never deletes history without
+  your explicit consent.
+- **Retroactive cleanup** with a Ctrl+Shift confirm. Apply the current
+  whitelist to an existing 800-MB+ database, watch it shrink to MBs, all on a
+  background thread.
+- **Export** to Markdown, JSON or CSV (GDPR Art. 15 right of access). Filter
+  by channel, date range or sender substring; written via Dalamud's file
+  dialog without blocking the UI.
+- **First-run wizard** with three profiles (Privacy-First / Casual / Full
+  History) that maps to concrete configuration sets. Reopenable from the
+  Privacy tab any time.
+- **Independent plugin state.** Config and database live under
+  `pluginConfigs/HellionChat/`, completely separate from upstream Chat 2 — you
+  can run both side by side, or migrate from Chat 2 once and keep going.
+- **Migration recovery.** Heals databases left in a half-applied Migrate3
+  state (columns added, `user_version` never bumped) without needing the
+  backup file upstream creates.
+- **Localized UI (EN + DE).** All Hellion-specific surfaces follow Dalamud's
+  language override and switch live. Translations live in
+  `Resources/HellionStrings.<lang>.resx`.
 
-### Chat Window
-![chatWindow.png](ChatTwo/images/chatWindow.png)
+## Status
 
-### With SimpleTweaks "Chat Name Colors"
-![withSimpleTweaks.png](ChatTwo/images/withSimpleTweaks.png)
+Bootstrap (v0.1.x). Used in production on a single user's setup. Not (yet)
+submitted to the official Dalamud plugin repository — distributed as a
+custom-repo / dev-plugin while the architecture stabilises.
 
----
+## Why a fork
 
-### IPC Integration
-Other plugins can easily integrate their functionality into the context menu of chat2
-For more infos read [IPC Guide](ipc.md)
+The upstream maintainer has left filtering-related issues open since 2024
+([#84](https://github.com/Infiziert90/ChatTwo/issues/84),
+[#173](https://github.com/Infiziert90/ChatTwo/issues/173),
+[#174](https://github.com/Infiziert90/ChatTwo/issues/174)). The original
+design treats the database as an unlimited searchable archive of *everything*
+the chat window sees, which is fine in the US-/JP-shaped privacy mindset but
+hard to reconcile with EU GDPR data minimization rules when the archive
+contains messages from third parties.
 
----
+Forking under EUPL-1.2 is explicitly permitted, the upstream stays
+authoritative for the chat-replacement engine, and we cherry-pick relevant
+upstream bugfixes from `Infiziert90/ChatTwo` periodically.
 
-### Thanks to
-The original dev Anna~
+## Build
+
+```bash
+# Linux with XIVLauncher Core
+cp .env.example .env
+# adjust DALAMUD_HOME if your hooks live somewhere else
+set -a; source .env; set +a
+dotnet build ChatTwo/ChatTwo.csproj
+```
+
+The output assembly is `ChatTwo/bin/Debug/HellionChat.dll`. Add the parent
+directory as a Dev Plugin Location in Dalamud's experimental settings.
+
+## Branding assets
+
+`ChatTwo/images/icon.png` is the upstream Chat 2 icon and stays in place
+until a hand-drawn Hellion logo replaces it. **No AI-generated artwork —
+ever.**
+
+## License
+
+EUPL-1.2 (same as upstream Chat 2). See `LICENCE`.
+
+## Acknowledgments
+
+- **Infi & Anna (ascclemens)** — original Chat 2 engine, filtering, IPC, all
+  the heavy lifting before this fork existed.
+- **Dalamud team** — the plugin framework underneath everything.
+- **JonKazama-Hellion** — fork maintenance, privacy/retention/export
+  features, German localization.
+
+## AI assistance disclosure
+
+See `AI_DISCLOSURE.md`.