Fix crash when hook entries have no matcher (#160)

Claude Code allows hook entries without a `matcher` field (e.g.,
SessionStart and SubagentStop hooks don't need one). The OpenCode
converter assumed `matcher.matcher` was always present, causing
"undefined is not an object (evaluating 'matcher.matcher.split')"
when converting plugins with matcher-less hooks.

Make `matcher` optional in the type and guard all accesses.

src/converters/claude-to-opencode.ts

@@ -209,9 +209,11 @@ function renderHookStatements(
 ): string[] {
   if (!matcher.hooks || matcher.hooks.length === 0) return []
   const tools = matcher.matcher
+    ? matcher.matcher
         .split("|")
         .map((tool) => tool.trim().toLowerCase())
         .filter(Boolean)
+    : []
 
   const useMatcher = useToolMatcher && tools.length > 0 && !tools.includes("*")
   const condition = useMatcher
@@ -232,10 +234,10 @@ function renderHookStatements(
       continue
     }
     if (hook.type === "prompt") {
-      statements.push(`// Prompt hook for ${matcher.matcher}: ${hook.prompt.replace(/\n/g, " ")}`)
+      statements.push(`// Prompt hook for ${matcher.matcher ?? "*"}: ${hook.prompt.replace(/\n/g, " ")}`)
       continue
     }
-    statements.push(`// Agent hook for ${matcher.matcher}: ${hook.agent}`)
+    statements.push(`// Agent hook for ${matcher.matcher ?? "*"}: ${hook.agent}`)
   }
 
   return statements

src/types/claude.ts

@@ -79,7 +79,7 @@ export type ClaudeHookAgent = {
 export type ClaudeHookEntry = ClaudeHookCommand | ClaudeHookPrompt | ClaudeHookAgent
 
 export type ClaudeHookMatcher = {
-  matcher: string
+  matcher?: string
   hooks: ClaudeHookEntry[]
 }