chore: housekeeping — linter & formatter setup

Add .prettierrc.json, .markdownlint.json, .yamllint.yaml, .gitattributes
Run CSharpier, Prettier and markdownlint across the entire codebase.
No logic changes — formatting, using order and line endings only.

SUPPORT.md

@@ -1,6 +1,7 @@
 # Support
 
-HellionChat is a small hobby project maintained by one person. There are a few different paths depending on what you need. Pick the one that matches.
+HellionChat is a small hobby project maintained by one person. There are a few different paths depending on what you
+need. Pick the one that matches.
 
 ## Bugs and feature requests
 
@@ -9,36 +10,45 @@ Gitea issues, using the templates:
 - [Bug report](https://gitea.hellion-forge.cloud/JonKazama-Hellion/HellionChat/issues/new?template=bug_report.yml)
 - [Feature request](https://gitea.hellion-forge.cloud/JonKazama-Hellion/HellionChat/issues/new?template=feature_request.yml)
 
-Please search [existing issues](https://gitea.hellion-forge.cloud/JonKazama-Hellion/HellionChat/issues?type=issue) first. Duplicates get closed and pointed at the original.
+Please search [existing issues](https://gitea.hellion-forge.cloud/JonKazama-Hellion/HellionChat/issues?type=issue)
+first. Duplicates get closed and pointed at the original.
 
 ## Security
 
-Do **not** open a public issue for security-relevant findings. Use the private advisory route described in [SECURITY.md](SECURITY.md):
+Do **not** open a public issue for security-relevant findings. Use the private advisory route described in
+[SECURITY.md](SECURITY.md):
 
 - Email `kontakt@hellion-media.de` (preferred for security reports)
 - Discord DM `@j.j_kazama` for time-sensitive findings
 
 ## Privacy questions
 
-Specific questions about what HellionChat does or does not store and send are covered in [PRIVACY.md](PRIVACY.md). For follow-ups beyond that document:
+Specific questions about what HellionChat does or does not store and send are covered in [PRIVACY.md](PRIVACY.md). For
+follow-ups beyond that document:
 
 - Email `kontakt@hellion-media.de`
 
 ## Quick questions and casual feedback
 
-- **Hellion Forge Discord** (community for HellionChat and other Hellion Online Media plugins and tools): https://discord.gg/X9V7Kcv5gR
+- **Hellion Forge Discord** (community for HellionChat and other Hellion Online Media plugins and tools):
+  [discord.gg/X9V7Kcv5gR](https://discord.gg/X9V7Kcv5gR)
 - Discord DM: `@j.j_kazama`
 
-Bug reports still go through the issue tracker so they can be tracked, but a quick "is this a bug or am I holding it wrong" message is fine.
+Bug reports still go through the issue tracker so they can be tracked, but a quick "is this a bug or am I holding it
+wrong" message is fine.
 
 ## Upstream Chat 2 issues
 
-If the issue exists in upstream Chat 2 too, please report it at [Infiziert90/ChatTwo](https://github.com/Infiziert90/ChatTwo/issues). That keeps the original maintainers in the loop and helps everyone who uses Chat 2 directly.
+If the issue exists in upstream Chat 2 too, please report it at
+[Infiziert90/ChatTwo](https://github.com/Infiziert90/ChatTwo/issues). That keeps the original maintainers in the loop
+and helps everyone who uses Chat 2 directly.
 
 ## Response times
 
-Weekdays during European business hours. On weekends and FFXIV patch days, replies will be slower. A few days of silence on a non-urgent issue is normal. Pinging once after a week is fine.
+Weekdays during European business hours. On weekends and FFXIV patch days, replies will be slower. A few days of silence
+on a non-urgent issue is normal. Pinging once after a week is fine.
 
 ---
 
-Maintained under **Hellion Forge**, the modding and plugin line of **Hellion Online Media** | Bad Harzburg | [hellion-media.de](https://hellion-media.de)
+Maintained under **Hellion Forge**, the modding and plugin line of **Hellion Online Media** | Bad Harzburg |
+[hellion-media.de](https://hellion-media.de)