Particular area and files to be tested

• ZimReaderContainer.kt
• ZimReaderSource.kt

Current Status of the tests
Incomplete. Both files contain significant testing gaps in core ZIM reading abstractions. Needs unit tests to improve coverage as requested in parent issue #4633.

Particular Behaviour to be tested

• ZimReaderContainer.kt: Execution paths for HTTP "Range" header handling in the load() function, redirect logic (isRedirect, getRedirect), routing methods (getPageUrlFromTitle), and property getters delegating to the file reader (fileSize, creator, language, etc.).
• ZimReaderSource.kt: Initialization branches (File vs. URI constructors), validation methods (exists(), canOpenInLibkiwix()), archive creation (createArchive()) handling AssetFileDescriptors, and standard data class methods (equals(), hashCode()).