docs: v0.125.0 path-strand fix — CHANGELOG + REPORT (probe transcript, red-proofs, round-trip evidence, Tier-1/2 mechanism) + CONTEXT + REUSE + README flows; hollow-bundle asymmetry recorded (containerized ≤0.124.0 exports suspect — re-export); floor note for the next train

Claude-Session: https://claude.ai/code/session_01GzammAMzsJTgpQHqxwM2bC

CONTEXT.md

@@ -7,7 +7,19 @@
 >
 > Ask Claude Code: "Please update CONTEXT.md with what we did today"
 
-Last updated: 2026-07-13 (v0.124.0 — backups IA restructure)
+Last updated: 2026-07-13 (v0.125.0 — .fab volume path-strand fix)
+
+> **2026-07-13 — v0.125.0: .FAB VOLUME PATH-STRAND DATA LOSS FIXED (IA finding 1, HIGH).
+> MinAgent 0.81 unchanged; floor may advance to 0.125.0 next train (must NOT halt above 0.124.0
+> without this).** Both volume legs stream via docker cp (helper container + `dockerExec` seam —
+> zero shared paths, correct bare-metal AND containerized; §3 live probe first). Export FAILS
+> LOUD on any missing/empty claimed tar (`assertBundleDataComplete`); import VALIDATES BEFORE it
+> destroys (`validateBundleData` in step 0 — hollow bundle → refusal, app untouched). Class
+> extinguished by `scripts/docker_run_volume_path_gate.py` (every `"-v"` allowlisted with WHY;
+> Tier-1/2 mounts documented host-visible). Live: the exact failed ActualBudget leg round-trips
+> byte-identically (`ec8ea6cb…` before==after); engine-invalid volume → loud export failure.
+> **ASYMMETRY (needs a customer-docs line):** .fab bundles exported by containerized ≤0.124.0
+> controllers are hollow — re-export; the import guard refuses them loudly.
 
 > **2026-07-13 — v0.124.0: BACKUPS IA RESTRUCTURE. MinAgent 0.81.0 + floor unchanged.
 > Operator decisions (2026-07-13, treat as settled):** (1) single active offsite destination per