fix(ios): move mime types to constants and fix readdir error for unknown extensions

- Move mimeTypes dictionary to NitroFSMimeTypes struct in Utils.swift
- Fix readdir to return 'application/octet-stream' for unknown extensions instead of throwing error
- Add support for SQL database file extensions (.db, .sqlite, .sqlite3, .sql)

Author: patrickkabwe

ios/NitroFSImpl.swift

@@ -159,23 +159,7 @@ class NitroFSImpl {
             return "application/octet-stream"
         }
 
-        let mimeTypes: [String: String] = [
-            "jpg": "image/jpeg",
-            "jpeg": "image/jpeg",
-            "png": "image/png",
-            "gif": "image/gif",
-            "pdf": "application/pdf",
-            "txt": "text/plain",
-            "json": "application/json",
-            "mp4": "video/mp4",
-            "mp3": "audio/mpeg",
-            "zip": "application/zip"
-        ]
-        
-        guard let mimeType = mimeTypes[pathExtension] else {
-            throw NitroFSError.encodingError(message: "Failed to get mime type")
-        }
-        return mimeType
+        return NitroFSMimeTypes.mimeTypes[pathExtension] ?? "application/octet-stream"
     }
 
     func rename(oldPath: String, newPath: String) throws {

ios/Utils.swift

@@ -20,6 +20,42 @@ struct NitroFSDirs {
     }
 }
 
+struct NitroFSMimeTypes {
+    static let mimeTypes: [String: String] = [
+        "jpg": "image/jpeg",
+        "jpeg": "image/jpeg",
+        "png": "image/png",
+        "gif": "image/gif",
+        "pdf": "application/pdf",
+        "txt": "text/plain",
+        "json": "application/json",
+        "mp4": "video/mp4",
+        "mp3": "audio/mpeg",
+        "zip": "application/zip",
+        "csv": "text/csv",
+        "xls": "application/vnd.ms-excel",
+        "xlsx": "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
+        "ppt": "application/vnd.ms-powerpoint",
+        "pptx": "application/vnd.openxmlformats-officedocument.presentationml.sheet",
+        "doc": "application/vnd.ms-word",
+        "docx": "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
+        "odt": "application/vnd.oasis.opendocument.text",
+        "ods": "application/vnd.oasis.opendocument.spreadsheet",
+        "db": "application/vnd.sqlite3",
+        "sqlite": "application/vnd.sqlite3",
+        "sqlite3": "application/vnd.sqlite3",
+        "sql": "application/sql",
+        "xml": "application/xml",
+        "yaml": "text/yaml",
+        "yml": "text/yaml",
+        "md": "text/markdown",
+        "readme": "text/plain",
+        "log": "text/plain",
+        "html": "text/html",
+        "htm": "text/html",
+    ]
+}
+
 enum NitroFSError: Error {
     case unavailable(message: String)
     case fileError(message: String)