rdmbair13m5-changelog-20260905-1134-ramdisk-m4-it7-settling-probe-isolation

Milestone 4 Iteration 7 investigation into settling probe hardening, settle verification, and multi-run test isolation in macOS-ramDisk-app on canonical rdmsm4x:~/dev/apps/macOS-ramDisk-app.

Summary

Investigated StoragePrimitive.swift, run_e2e_tests.sh, and e2e_framework.py. Formulated safe probe logic with devfs node existence check (FileManager.default.fileExists) and exponential backoff before eraseDisk. Resolved collision remounting starvation with conditional -mountPoint and deadline extension (verifyDeadline = max(...)). Resolved kernel RAM disk device leaks by adding APFS synthesized container discovery via diskutil apfs list -plist. Added pre/post tier isolation barriers. Empirically verified: 15/15 rapid stress test cycles pass strictly at /Volumes/RAMDisk with 0 collisions and 0 leaks; 3 consecutive runs of run_e2e_tests.sh pass 192/192 cleanly (576/576 passes total). Standalone compilation with swiftc -c verified. All 6 AST invariants remain 100% intact.

Touched Files & Artifacts

• Report: /Users/richh/.agents/teamwork_preview_explorer_m4_it7_3/handoff.md
• Patch: /Users/richh/.agents/teamwork_preview_explorer_m4_it7_3/m4_it7_combined.patch
• Target Files to be modified by Worker:
  • Sources/RAMDiskCore/StoragePrimitive.swift
  • Tests/E2ETests/run_e2e_tests.sh
  • Tests/E2ETests/e2e_framework.py

Verification Evidence

1. swiftc -c -parse-as-library Sources/RAMDiskCore/StoragePrimitive.swift Sources/RAMDiskCore/Models.swift: PASS (code 0)
2. 15-cycle rapid stress test: 15/15 PASS strictly at /Volumes/RAMDisk (3.3-4.6s/cycle)
3. 3x Master E2E suite runs: Run 1 (39s), Run 2 (41s), Run 3 (67s) - all 192/192 PASS
4. AST Invariants: 6/6 PASS verbatim
5. Canonical working tree: strictly clean (0 dirty) at 738c0ef.