chore: ignore UpgradeLog.htm in oxfmt config

The course material includes UTF-16 VS upgrade logs that oxfmt cannot
read, which broke `npx oxfmt --check .`. Ignore them by filename.

Also include the SKILL.md frontmatter rewrap from the formatter run.

Co-authored-by: Qwen 3.8 27B <qwen3.8_27b-q3_k_xl@lmstudio.local>

.agents/skills/git/SKILL.md

@@ -2,8 +2,8 @@
 name: git
 description: >-
   Git workflow: commit message format, co-author trailers, tagging, and
-    branching conventions. Use when committing changes, creating release tags,
+  branching conventions. Use when committing changes, creating release tags, or
-    or following branch naming rules.
+  following branch naming rules.
 ---
 
 # Git Skill

.oxfmtrc.json

@@ -1,5 +1,5 @@
 {
-  "ignorePatterns": ["node_modules", "dist", ".git"],
+  "ignorePatterns": ["node_modules", "dist", ".git", "UpgradeLog.htm"],
   "overrides": [
     {
       "files": ["*.md"],