refactor: simplify editor initialization by removing custom formatting

Standardize skill file structure to use SKILL.md in subdirectories for all editors.
Remove cursor-specific .mdc format and copilot marker injection logic.

Author: locchh

src/commit_explorer/init.py

@@ -23,14 +23,7 @@
     "claude":   ".claude/skills",
     "windsurf": ".windsurf/skills",
     "cursor":   ".cursor/skills",
-    "copilot":  ".github/skills",
-}
-
-_EDITOR_EXT = {
-    "claude":   ".md",
-    "windsurf": ".md",
-    "cursor":   ".mdc",
-    "copilot":  None,
+    "copilot":  ".copilot/skills",
 }
 
 
@@ -49,55 +42,6 @@ def _fetch_skill(name: str) -> str:
     return _get(f"{_RAW_BASE}/{name}/SKILL.md")
 
 
-def _split_frontmatter(content: str) -> tuple[dict[str, str], str]:
-    if not content.startswith("---"):
-        return {}, content
-    end = content.index("---", 3)
-    fm: dict[str, str] = {}
-    for line in content[4:end].splitlines():
-        if ":" in line:
-            k, _, v = line.partition(":")
-            fm[k.strip()] = v.strip()
-    return fm, content[end + 3:].lstrip("\n")
-
-
-def _cursor_mdc(fm: dict[str, str], body: str) -> str:
-    desc = fm.get("description", "")
-    if len(desc) > 120:
-        desc = desc[:117] + "..."
-    return f"---\ndescription: {desc}\nglobs: \nalwaysApply: false\n---\n\n{body}"
-
-
-def _copilot_marker(name: str) -> str:
-    return f"<!-- cex-skill:{name} -->"
-
-
-def _write_copilot(skills: dict[str, str], target: Path) -> None:
-    out = target / ".github" / "skills" / "copilot-instructions.md"
-    out.parent.mkdir(parents=True, exist_ok=True)
-
-    if out.exists():
-        text = out.read_text(encoding="utf-8")
-        for name, body in skills.items():
-            marker = _copilot_marker(name)
-            if marker in text:
-                # replace between this marker and the next (or EOF)
-                start = text.index(marker)
-                next_marker = text.find("<!-- cex-skill:", start + len(marker))
-                end = next_marker if next_marker != -1 else len(text)
-                text = text[:start] + f"{marker}\n{body}\n" + text[end:]
-            else:
-                text = text.rstrip("\n") + f"\n\n{marker}\n{body}\n"
-        action = "Updated"
-    else:
-        parts = [f"{_copilot_marker(n)}\n{b}" for n, b in skills.items()]
-        text = "\n\n".join(parts) + "\n"
-        action = "Created"
-
-    out.write_text(text, encoding="utf-8")
-    print(f"  {action}: {out.relative_to(target)}")
-
-
 def run_init(editor: str, target: Path = Path(".")) -> None:
     print(f"Fetching skills from {_REPO} ({_BRANCH})…", file=sys.stderr)
     try:
@@ -111,8 +55,6 @@ def run_init(editor: str, target: Path = Path(".")) -> None:
         return
 
     out_dir = target / _EDITOR_DIR[editor]
-    ext = _EDITOR_EXT[editor]
-    copilot_skills: dict[str, str] = {}
 
     for name in names:
         print(f"  Downloading: {name}", file=sys.stderr)
@@ -122,22 +64,8 @@ def run_init(editor: str, target: Path = Path(".")) -> None:
             print(f"  Warning: could not fetch {name}: {exc}", file=sys.stderr)
             continue
 
-        fm, body = _split_frontmatter(raw)
-
-        if editor == "copilot":
-            copilot_skills[name] = body
-            continue
-
-        out_dir.mkdir(parents=True, exist_ok=True)
-        dest = out_dir / f"{name}{ext}"
+        dest = out_dir / name / "SKILL.md"
+        dest.parent.mkdir(parents=True, exist_ok=True)
         action = "Updated" if dest.exists() else "Created"
-
-        if editor == "cursor":
-            dest.write_text(_cursor_mdc(fm, body), encoding="utf-8")
-        else:
-            dest.write_text(raw, encoding="utf-8")
-
+        dest.write_text(raw, encoding="utf-8")
         print(f"  {action}: {dest.relative_to(target)}")
-
-    if editor == "copilot" and copilot_skills:
-        _write_copilot(copilot_skills, target)