Mesh: built-in runtime observability canvas for nodes, actors, and message flow

[snowdamiz]

Outcome

Add built-in runtime observability to Mesh so operators can see clustered nodes and actor activity visually: nodes joining and dying, actors spawning and respawning, and data/messages traveling across the system in real time.

Scope

• Runtime-owned observability surface for node and actor topology
• Structured lifecycle events for node join/leave/failure and actor spawn/exit/restart
• Message/data-flow telemetry suitable for live visualization
• A visual canvas/operator surface that can render nodes, actors per node, traffic between them, and failure/recovery behavior
• A truth-preserving surface that both Hyperpush and self-hosted Mesh operators can consume

Acceptance criteria

• Operators can see nodes and actor placement visually on a canvas
• Node death, recovery, and cluster membership changes are visible in near real time
• Actor spawn, death, and respawn are visible in near real time
• Message or data movement between nodes/actors is represented visually and grounded in real runtime data
• The observability contract is stable enough to support both product and self-hosted operator use cases

Detailed acceptance criteria

• Runtime telemetry must expose real node and actor state rather than inferred UI-only models.
• Operators must be able to see node membership, actor placement, spawn/death/respawn, and cross-node flow.
• Failure and recovery visuals must be grounded in real runtime events.
• The observability surface must support both Hyperpush and generic Mesh operator use cases.

Initial sub-issues

• Mesh observability: emit structured runtime topology and actor lifecycle events #16 — Mesh observability: emit structured runtime topology and actor lifecycle events
• Mesh observability: capture message and work movement for live cluster visualization #17 — Mesh observability: capture message and work movement for live cluster visualization
• Mesh observability: build operator canvas for nodes, actors, failures, and respawns #18 — Mesh observability: build operator canvas for nodes, actors, failures, and respawns