refactor: replace concrete type switch with ExecutionTrackerSetter interface

[intel352]

Summary

• Defines an ExecutionTrackerSetter interface in cmd/server/main.go alongside the other local server interfaces (pipelineEventSetter, executionTrackerIface, etc.)
• Replaces the two-case type switch on *module.QueryHandler / *module.CommandHandler in registerPostStartServices with a single interface assertion
• No behavior change — both concrete types already have a matching SetExecutionTracker(module.ExecutionTrackerProvider) method

Motivation

The old switch required editing the server file every time a new module type needed execution tracking. With the interface, any new module that implements SetExecutionTracker(module.ExecutionTrackerProvider) is automatically wired without touching cmd/server/main.go.

Test plan

• go build ./... passes
• go test ./... passes (all packages green)
• golangci-lint run ./cmd/server/ reports 0 issues
• Pre-push hooks passed

closes #62

🤖 Generated with Claude Code

[Copilot]

Pull request overview

Refactors the server’s post-start wiring to use an interface assertion instead of a concrete-type switch when injecting the execution tracker into CQRS handlers, reducing the need to update cmd/server/main.go as new handler types are added.

Changes:

• Introduces an ExecutionTrackerSetter interface in cmd/server/main.go.
• Replaces the *module.QueryHandler / *module.CommandHandler type switch with a single ExecutionTrackerSetter assertion in registerPostStartServices.

Comments suppressed due to low confidence (1)

cmd/server/main.go:246

• ExecutionTrackerSetter is exported while all other “minimal interfaces” in this section are unexported (e.g., v1StoreIface, pipelineEventSetter, executionTrackerIface). Since this is only used internally in cmd/server/package main, consider making it unexported (e.g., executionTrackerSetter) to match the established naming convention and avoid implying a public API surface.

// ExecutionTrackerSetter is implemented by any module that accepts an
// ExecutionTrackerProvider. Using this interface in place of a concrete-type
// switch means the server does not need to be modified when new module types
// require execution tracking.
type ExecutionTrackerSetter interface {
	SetExecutionTracker(module.ExecutionTrackerProvider)
}