Add fresher-qa module: 50 Java interview questions for freshers, one runnable demo each, asserted transcripts, javac error captures

Co-Authored-By: Claude Sonnet 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_017ic4b5DfjBGLBr7F5km2AN

fresher-qa/output/07-compile-errors.txt

@@ -0,0 +1,38 @@
+=== javac FinalOverride.java ===
+FinalOverride.java:6: error: locked() in Derived cannot override locked() in Base
+    String locked() { return "Derived.locked"; }
+           ^
+  overridden method is final
+1 error
+
+=== javac CheckedNotHandled.java ===
+CheckedNotHandled.java:6: error: unreported exception IOException; must be caught or declared to be thrown
+        String s = Files.readString(Path.of("missing.txt"));
+                                   ^
+1 error
+
+=== javac LossyCast.java ===
+LossyCast.java:3: error: incompatible types: possible lossy conversion from double to int
+        int x = 3.5;
+                ^
+LossyCast.java:4: error: incompatible types: possible lossy conversion from int to byte
+        byte b = 200;
+                 ^
+2 errors
+
+=== javac MissingReturnAndUnreachable.java ===
+MissingReturnAndUnreachable.java:4: error: missing return statement
+    }
+    ^
+1 error
+
+=== javac --release 21 PreSuper.java ===
+PreSuper.java:8: error: flexible constructors is not supported in -source 21
+        super();
+             ^
+  (use -source 25 or higher to enable flexible constructors)
+1 error
+
+=== javac --release 25 PreSuper.java ===
+compiled without errors
+