Fix Cascading Graph Deletion Bug inside FileSystemIngestor

Bug Description

A critical regression caused ~50,000 structural graph nodes to be wiped from the memory-core.sqlite database natively due to a cascading deletion bug between the FileSystemIngestor edge assertions and the Vector Apoptosis loop in DreamService.

Root Cause

1. Top-level files and directories generated by FileSystemIngestor lacked a root parentId, bypassing CONTAINS edge creation.
2. DreamService's Vector Apoptosis process deletes unanchored (edge-less) nodes, therefore culling the workspace root nodes.
3. On the next GC loop, SQLite edges referencing the now-culled root nodes were deleted to maintain referential integrity.
4. Because FileSystemIngestor skips re-evaluating edges for files whose mtimeMs/hash have not changed (isUnchanged), the missing edges were never recreated.
5. In the subsequent Apoptosis runs, the child nodes sequentially lost their physical anchors bottom-up and were annihilated natively.

Proposed Resolution

• Anchor the workspace natively to a project-root (SYSTEM_ANCHOR) node, newly dubbed "Neo.mjs Ecosystem Root", so root structures always maintain edge-health validation natively inside the graph.
• Relocate edge creation strictly outside the isUnchanged file-hashing check inside FileSystemIngestor.walkDirectory() so that topology drift is autonomously healed without requiring full MTime disk thrashing.