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/01-basics.txt

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+=== Q01 Why is Java platform independent? ===
+magic = CAFEBABE
+class file major version = 69
+=== Q02 JDK vs JRE vs JVM ===
+running on Java 25
+JVM: OpenJDK 64-Bit Server VM
+compiler available: true
+=== Q03 Primitive types and their sizes ===
+byte   1 byte,  -128 to 127
+short  2 bytes, -32768 to 32767
+int    4 bytes, -2147483648 to 2147483647
+long   8 bytes, -9223372036854775808 to 9223372036854775807
+float  4 bytes, double 8 bytes, char 2 bytes
+field defaults: 0, false, null
+=== Q04 Type casting and overflow ===
+7 / 2 = 3, (double) 7 / 2 = 3.5
+(byte) 130 = -126
+Integer.MAX_VALUE + 1 = -2147483648
+c + 1 = 66, (char) (c + 1) = B
+0.1 + 0.2 = 0.30000000000000004
+Math.addExact: integer overflow
+=== Q05 Autoboxing and the Integer cache ===
+127 == 127 -> true
+128 == 128 -> false
+128 equals 128 -> true
+Long 127 equals Integer 127 -> false
+=== Q06 Is Java pass by value or pass by reference? ===
+after reassign: original
+after mutate:   original + mutated
+=== Q07 static variables, static blocks and initialisation order ===
+static block runs once, when the class loads
+instance block runs before each constructor body
+constructor #1
+instance block runs before each constructor body
+constructor #2
+=== Q08 final, finally and finalize ===
+final array contents changed: 99
+in try
+finally always runs
+Object.finalize forRemoval = true, since 9
+=== Q09 Stack vs heap ===
+heap array length = 1000000
+StackOverflowError after many frames: true