feat(release): 2.0.0 -- nine cycles ship, and the config starts over

v1.6.0 through v1.15.0 were never published. The whole window layer was being
rewritten from ImGui defaults to custom drawing, and repo.json deliberately kept
its links on v1.5.6 so nobody could update into a half-finished state. That work
lands here in one release.

The config is not migrated, it is replaced. A config carried across nine cycles of
window rebuilds holds values chosen against surfaces that no longer exist, and
starting over is the only way to be sure every install is on the same defaults.
The message database is a separate file and is not touched. The old config is
copied to HellionChat.json.pre-2.0.0.bak first, so rolling back to 1.5.6 stays a
file copy rather than an evening of clicking settings back in.

Config schema 27. The reset runs from the constructor, before LoadAsync seeds the
default tabs, and the self-test now fails if the tab list is empty at /xlperf --
that ordering breaking would leave every user with no tabs and nothing else in the
plugin would notice.

Default layout gains an Emote tab: custom emotes, standard emotes and echo. A
tester asked for it, emotes get lost between system notices otherwise.

Manifest, README, roadmap and the four changelog consumers are on 2.0.0. The
release notes lead with what was fixed rather than what was redrawn -- retroactive
cleanup that could never be applied, a compaction that reported deleting nothing
while deleting everything, pinned tell tabs that came up empty for a session. And
with the one behaviour change users should know about: the channel grid is
authoritative over storage now, so anyone who had unticked channels while the
unknown-channel failsafe was on stores less than they did before.

README.md

@@ -2,7 +2,7 @@
 
 [![Build](https://gitea.hellion-forge.cloud/JonKazama-Hellion/HellionChat/actions/workflows/build.yml/badge.svg?branch=main)](https://gitea.hellion-forge.cloud/JonKazama-Hellion/HellionChat/actions/workflows/build.yml)
 [![License: EUPL-1.2](https://img.shields.io/badge/License-EUPL--1.2-blue.svg)](LICENSE)
-[![Latest release](https://img.shields.io/badge/release-v1.5.6-brightgreen)](https://gitea.hellion-forge.cloud/JonKazama-Hellion/HellionChat/releases/latest)
+[![Latest release](https://img.shields.io/badge/release-v2.0.0-brightgreen)](https://gitea.hellion-forge.cloud/JonKazama-Hellion/HellionChat/releases/latest)
 [![Dalamud API](https://img.shields.io/badge/Dalamud-API_15-purple)](https://github.com/goatcorp/Dalamud)
 [![.NET](https://img.shields.io/badge/.NET-10.0-512BD4)](https://dotnet.microsoft.com/)
 [![FFXIV](https://img.shields.io/badge/FFXIV-Dawntrail-c3a37f)](https://www.finalfantasyxiv.com/)
@@ -11,8 +11,8 @@
   <img src="docs/images/hellion-forge.png" alt="Hellion Forge" width="180" />
 </p>
 
-**Version 1.5.6** — Privacy-first chat plugin for FINAL FANTASY XIV / Dalamud, built on
-[Chat 2](https://github.com/Infiziert90/ChatTwo) (EUPL-1.2).
+**Version 2.0.0** — Privacy-first chat plugin for FINAL FANTASY XIV / Dalamud, originally
+forked from [Chat 2](https://github.com/Infiziert90/ChatTwo) (EUPL-1.2).
 
 Hellion Chat is a privacy-first plugin built on the Chat 2 foundation. The majority of the engine
 comes from Chat 2 (message store, channel logic, hook system), and most keyboard shortcuts continue
@@ -301,6 +301,15 @@ An optional submission to the Dalamud main plugin repo (in addition to the custo
 
 ## Project Status
 
+**Version 2.0.0** — Rebuilt, Repaired, Reset. Nine development cycles replaced every
+window in the plugin: the sidebar, tab strip and status bar, the settings window, the
+message list, the input row and the first-run wizard are drawn by the plugin rather than
+by ImGui defaults, and share one visual language. Typography carries structure, anything
+you can press gets a surface, and colours are measured against what sits behind them.
+**This update resets your settings** — nine cycles of window rebuilds left saved values
+pointing at surfaces that no longer exist. The message database is untouched and the old
+config is kept alongside it as `HellionChat.json.pre-2.0.0.bak`.
+
 **Version 1.5.6** — Settings Overhaul + Filter & Notification Polish. The Settings window
 has been reorganised from ten tabs to seven (General, Appearance, Chat, Window, Channels,
 Data & Privacy, About). Each tab now uses collapsible sections grouped by control type;