[feat] Memory corruption attack categories + kernel triage layer

[peaktwilight]

What

Extend AttackCategory union type with memory corruption classes:

• heap-overflow
• use-after-free
• stack-buffer-overflow
• null-pointer-deref
• integer-overflow
• race-condition
• type-confusion
• double-free

Add kernel_oracle to TriageLayerName.

Extend feature-extractor with kernel-specific features (crash type, stack depth, subsystem, reproducer presence).

Extend PoV gate CATEGORY_JUDGES with kernel-specific proof patterns.

none

[peaktwilight]

Implemented in 5899942. 8 new AttackCategory values (heap-overflow, use-after-free, stack-buffer-overflow, null-pointer-deref, integer-overflow, race-condition, type-confusion, double-free), kernel_oracle triage layer, CrashReport/CrashType types.