[DOCS][NARRATOR] Architecture Diagram: Zero-GC Panama Off-Heap Memory Lifecycle & WAL

[novaspectrayan]

Summary

One of Spector's most impressive engineering feats is storing millions of vector engrams in native off-heap memory using Java 25's Foreign Function & Memory (FFM) API with zero Garbage Collection pauses.

We need an architectural sequence diagram illustrating the lifecycle of a memory block:

1. Arena Allocation (Arena.ofShared())
2. Ingestion & WAL Append (synchronous durability)
3. Direct Memory Segment Write (Panama MemorySegment)
4. Recycled or Compaction Lifecycle

Deliverables

• Add visual Mermaid sequence diagrams to docs/kernel/wal-recovery.md and docs/kernel/bundles.md.

Acceptance Criteria

• Accurate representation of Panama off-heap memory semantics.
• Render tested with MkDocs Material.