[jonbaldie]

Summary

README Docker persistence path
  PERSIST=/data/ -> documented, starts, persists across container recreation
  PERSIST=/mnt/  -> rejected/prohibited in README documentation

Issue #174 reported that the README's persistence command used PERSIST=/mnt/, causing startup crashes due to /mnt permissions for the non-root deno user.

Investigation revealed:

• PR fix: make Docker persistence path writable by the non-root user (#114) #119 (d61d8fd) had already updated the README copy-paste command from PERSIST=/mnt/ to PERSIST=/data/, added /data owned by deno as a VOLUME in Dockerfile, and defaulted PERSIST=/data/.
• Running the documented README persistence command starts cleanly and passes tests/docker_persist_test.ts.
• The failure observed during the 2026-10-17 exploratory pass occurred because the test command explicitly passed -e PERSIST=/mnt/ (an artifact from earlier pre-fix: make Docker persistence path writable by the non-root user (#114) #119 test scripts) rather than using the command documented in the README.
• Added explicit assertions in tests/readme_quick_start_test.ts (fast unit test without Docker) and tests/docker_persist_test.ts to ensure the README persistence command never regresses to /mnt/ and explicitly configures /data/.

Closes #174

Evidence

• Before & After: README.md already specifies PERSIST=/data/.
• Verbatim README command execution (docker run ... PERSIST=/data/ ...): starts and listens on 0.0.0.0:1991.
• Fast static test tests/readme_quick_start_test.ts: passes in 1ms.
• Full Docker persistence test tests/docker_persist_test.ts: passes with container start, enqueue, recreation, and dequeue.
• Production quality gate npm run quality:production: passes.

Merge Danger

Door: two-way

Blast Radius: test

Test-only additions locking down README documentation invariants. No runtime or dependency changes.