JVNAUTOSCI-916: concurrent scoped turns and multi-org tabs

[witbrock]

Outcome

Von can execute turns concurrently across different conversations while retaining FIFO single-flight within each conversation. Actor, organisation, namespace, request, attempt, task, and queue lifecycle are correlated exactly. One user can keep different organisations in different tabs without browser-wide scope leakage.

Architecture

• server-owned durable conversation admission and terminal reconciliation
• per-actor and global active limits, bounded durable backlog, typed backpressure
• HTTP-thread headroom derived from Waitress capacity; OpenStack default aligned to 32 threads
• exact actor/org/namespace task and progress access
• per-conversation frontend scheduler with independent Thinking/progress/abort state
• duplicate-tab window identity repair and explicit Personal scope semantics

Validation

• 121 affected backend tests passed
• 8 affected frontend suites, 319 tests passed
• stepped 10/20/50-user admission/recovery workload passed
• 20 users x 2 active-or-queued turns passed with exact visibility isolation
• actual Google Chrome duplicate-tab identity and reload validation passed
• independent final review found no remaining stop-ship defect
• diff check, targeted Python lint/format, frontend lint, and main compilation passed

Bounded claim

This targets one application process. It does not certify provider/model throughput, real-Mongo multi-process operation, or public adversarial SaaS tenancy. BroadcastChannel-less duplicate-tab collision handling and first-bind FIFO for pre-upgrade queue rows remain bounded limitations.

No deployment or activation is included. No Sol-family model was invoked.

Jira: JVNAUTOSCI-916