chore(release): v1.5.0 manifest bump

Version strings bumped across all eight tracked surfaces:

- HellionChat/HellionChat.csproj   <Version>1.5.0</Version>
- repo.json                        AssemblyVersion + TestingAssemblyVersion = 1.5.0.0
- repo.json                        three DownloadLink* URLs -> /v1.5.0/latest.zip
- repo.json                        Changelog field synced with yaml
- HellionChat/HellionChat.yaml     new v1.5.0 changelog block on top; v1.4.7
                                   drops out per the four-block slim rule
- docs/CHANGELOG.md                v1.5.0 entry prepended
- docs/ROADMAP.md                  Next Cycle pointer moves to v1.5.1, v1.5.0
                                   joins the released-cycle archive block
- README.md                        three status surfaces (badge, header,
                                   Project Status long-form) on v1.5.0
- .github/forge-posts/v1.5.0.md    Discord announcement body (German)

Preflight blocks A-F all green. Changelog embed total 2050 / 5500 chars
(four subblocks), forge-post frontmatter inside the 60/40 char caps.

Tag, push, merge are reserved for Flo.

docs/CHANGELOG.md

@@ -10,6 +10,46 @@ to the release pages for details.
 
 ---
 
+## Hellion Chat 1.5.0 — DI Foundation and Service Refactor (2026-05-17)
+
+Major architecture cycle. The plugin bootstrap moves to a generic-host DI container
+(`Microsoft.Extensions.Hosting` + `IServiceCollection`) modelled on Lightless Sync. Service
+logging migrates from a static `Plugin.LogProxy` locator to typed
+`Microsoft.Extensions.Logging.ILogger<T>` via constructor injection, bridged over Dalamud's
+`IPluginLog` by a custom `DalamudLogger` trio.
+
+### Under the hood
+
+- 18 instance-class services migrate to `ILogger<T>` via constructor injection across four
+  slices: data layer (`MessageStore`, `MessageManager`, `AutoTellTabsService`), IPC and
+  integrations (`HonorificService`, `IpcManager`, `TypingIpc`, `ExtraChat`, three
+  `GameFunctions` classes), UI window layer (`ChatLogWindow`, `DbViewer`, `Popout`, three
+  settings tabs), and root (`Commands`, `ThemeRegistry`, `PayloadHandler`).
+- `Plugin.LogProxy` stays in place for the eight buckets ctor injection cannot reach:
+  static helpers (`EmoteCache`, `AutoTranslate`, `MemoryUtil`, `WrapperUtil`),
+  Dalamud-reflected types (`Configuration`), the `Message` data class, and instance classes
+  that only log from static methods (`FontManager`, one `GameFunctions` site).
+- Plugin.cs finishes at 1012 lines — virtually identical to the pre-cycle 1013. The new
+  Phase-1 host build and `Plugin.X` bridge wiring trade out exactly the service and window
+  allocations that previously lived in `LoadAsync`.
+- Cross-plugin baseline confirms no performance penalty against Chat 2: HellionChat
+  first-frame HITCH 77 ms median, Chat 2 74 ms median. Lightless and XIVInstantMessenger sit
+  around 7 ms by deferring their font-atlas build past `Finished loading` — that pattern is
+  the v1.5.1 follow-up item.
+
+### User-visible
+
+- Slash-command insert fix: pasting a slash command into the chat input (Friend List
+  "/tell" action, plugin-driven inserts from Artisan, AllaganTools etc.) now replaces the
+  existing input instead of concatenating onto whatever the user was typing. Cherry-picked
+  from ChatTwo upstream `ee7768ac` with namespace adaptation.
+
+Migration v17 stays (no schema bump).
+
+Based on Chat 2 1.35.3 (upstream Infiziert90/ChatTwo, EUPL-1.2).
+
+---
+
 ## Hellion Chat 1.4.10 — Symbol-Picker and Tell-History Fix (2026-05-16)
 
 Eleventh and final sub-patch of the v1.4.x Polish-Sweep series. Symbol picker for the chat input, a tell-history reload fix