Architecture backlog: sandbox hardening toward web-readiness

[bartul]

Purpose

Track architecture decisions and prioritized improvements for the current local sandbox phase and future web robustness.

Scope

• Decision records (stored as GitHub issues, not docs ADRs)
• Actionable improvement issues with priority labels

Accepted constraints

• Local sandbox now, robust web later
• In-memory persistence now, JSON file persistence later
• Preview dependencies are acceptable for learning

Child issues

• Decision issues: linked in comments
• Improvement issues: linked in comments

Tracking

Use this issue as the parent reference for related work.

[bartul]

Linked child issues

Decisions

• Decision: Store architecture decisions in GitHub issues (not docs ADR files) #67 Decision: Store architecture decisions in GitHub issues
• Decision: Ignore inbound accounting events for unknown/uninitialized games (sandbox phase) #68 Decision: Ignore inbound accounting events for unknown/uninitialized games (sandbox)
• Decision: Keep in-memory persistence now, add JSON file persistence later #69 Decision: Keep in-memory persistence now, add JSON later

Improvements

• Improve host fault tolerance: supervise mailbox processing in RondelHost and AccountingHost #70 Host mailbox fault tolerance supervision
• Improve bus reliability: isolate subscriber failures and harden concurrent subscription safety #71 Bus subscriber fault isolation and concurrency safety
• Add failure-mode tests for host supervision and bus fault isolation #72 Failure-mode tests for host/bus resilience
• Improve RondelView safety: remove Option.Value assumptions and avoid blocking query flow #73 RondelView safety hardening
• Design host Execute acknowledgement semantics (deferred decision) #74 Host Execute acknowledgement semantics (deferred design)
• Plan JSON file persistence adapter for terminal store (deferred) #75 JSON file persistence adapter planning (deferred)
• Plan transactional outbox/retry strategy for save-publish-dispatch consistency (deferred) #76 Outbox/retry consistency strategy planning (deferred)