[Diagram Editor] Progress tracing and message-flow visualization

[ArizmendiWan]

Workflow activity can be missed during bursts, and message-flow feedback needs to distinguish individual executions of the same operation. This draft preserves the progress-visualization work separated from #219 so its runtime model can be reviewed independently.

• Add operation start/finish tracing, execution IDs, and tracing for join/listen operations.
• Batch WebSocket feedback and drain queued feedback before the finish response.
• Animate message activity on edges, track concurrent executions, and play back queued activity through completion.
• Update the API schema/types and include the edge-glow and WebSocket burst checks.

This PR targets main independently of #219. It retains the lifecycle-tracker implementation for review; the concerns about operation-owned activity state in #206 and the review on #219 are still open. Related: #225. Design work for #206 remains outstanding.

Validation

• TypeScript, Biome, and Rust formatting checks pass.
• 146 frontend unit tests and 13 REST integration cases pass. The integration cases were rerun separately after a stalled frontend build in the initial combined run.
• 17 backend tests pass; the normally ignored WebSocket burst test also passes when explicitly enabled.
• Production frontend rebuilt for this scope.
• Recombining the two source diffs exactly reproduces the original PR source at c5c45c2; an independent split review found no lost changes or cross-PR source dependencies.

The generated frontend archive must be rebuilt when combining this PR with #219.

GenAI Use

We follow OSRA's policy on GenAI tools.

• I used a GenAI tool in this PR.
• I did not use GenAI.

Generated-by: Codex