fix: settle orphaned evaluating interjections

[sam-saffron-jarvis]

What

Settle locally persisted interjection messages that remain evaluating after authoritative session state is idle and no live client transaction still owns them.

• tracked pending commits/interjections remain untouched
• orphaned evaluating messages transition to failed
• the settled state is persisted, so reload does not resurrect the spinner

Why

An interjection is first rendered optimistically and persisted as a client-owned transcript intent. Its in-memory pendingInterruptCommits bookkeeping is not persisted. After a reload or interrupted recovery, the message can therefore survive forever as evaluating even though:

• the server reports active_run: false
• there is no server pending_interjection
• there is no local pending commit or interjection transaction

Observed on session 3137: “this is taking forever” remained evaluating… for three hours while the server was idle and later turns had completed.

Invariant

An inline interjection may show evaluating only while a matching local pending commit or pending interjection transaction exists. Idle reconciliation marks unowned evaluating intents failed rather than leaving an immortal spinner.

Verification

• node internal/serveui/static/app_stream_test.js
• node internal/serveui/static/app_sessions_test.js
• go test ./internal/serveui/...
• go build .