Stabilize Decodex account run capsules

[yvette-carlisle]

Summary

• mark runActivity payloads as complete vs subscription-filtered so clients do not interpret filtered omissions as ended runs
• make the Decodex App and browser dashboard replace active runs only for complete payloads, preserving active snapshot rows only for explicit partial payloads
• assign account-row capsules from selected accounts[] entries when the primary account field is missing

Verification

• swift test --package-path apps/decodex-app
• cargo make checks
• semantic drift audit: pass; docs claim matches operator_http complete/filtered fields and App/dashboard consumers