fix: Use correct ProseMirror mark types (strong/em)

Outline schema uses:
- "strong" not "bold"
- "em" not "italic"

Error was: "RangeError: There is no mark type bold in this schema"

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/index.ts

@@ -39,7 +39,7 @@ async function main() {
   // Create MCP server with shared configuration
   const server = createMcpServer(pgClient.getPool(), {
     name: 'mcp-outline-postgresql',
-    version: '1.3.14'
+    version: '1.3.15'
   });
 
   // Connect stdio transport