Move version/commitSHA vars out of internal/cli into a leaf package

[rh-hemartin]

What happens

version and commitSHA are vars in internal/cli (root.go:9-10), set via -ldflags -X at build time. Any package that needs the version string must either import cli (which pulls in cobra, every subcommand, and all of cli's transitive dependencies) or receive it as a function parameter threaded from the call site.

Today telemetry.Setup() takes serviceVersion string as a parameter because internal/telemetry cannot import internal/cli without creating a cycle (cli already imports telemetry). The same threading happens in internal/binary/crosscompile.go, which reconstructs the ldflags path to inject the version into cross-compiled binaries.

What should happen

The two build-time vars and their accessors (Version(), CommitSHA()) should live in a dependency-free leaf package (e.g. internal/buildinfo) that any internal package can import without risk of cycles. The -ldflags -X paths in Makefile:102 and internal/binary/crosscompile.go:64 would update to point at the new package.

Callers that currently receive the version as a parameter (telemetry.Setup, and any future packages that need it) could import buildinfo directly instead of threading the value through multiple call sites.

Context

Came up during the OTel SDK migration (refactor/otel-sdk). telemetry.Setup needs the version to set service.version on the OTel resource, but can't import cli. Threading the string works, but as more packages need build metadata (the OTLP exporter, the OTel resource, user-agent headers), the parameter-passing accumulates. A leaf package removes the problem at the root.

[fullsend-ai-triage]

🤖 Finished Triage · ✅ Success · Started 8:04 AM UTC · Completed 8:08 AM UTC
Commit: 5cd495a · View workflow run →

[fullsend-ai-triage]

Triage Summary

Category: Refactoring (code organization) · Severity: Medium · Status: Ready for implementation

Problem

Build-time variables (version, commitSHA) in internal/cli/root.go sit high in the dependency graph. Packages that need version metadata either create import cycles or must receive the value as a threaded parameter. This is already visible in telemetry.Setup() and internal/binary/crosscompile.go, and will compound as more consumers need build metadata.

Root Cause

The vars live in a package with heavy transitive dependencies (cobra, all subcommands) rather than in a dependency-free leaf package.

Recommended Fix

1. Create internal/buildinfo/buildinfo.go as a zero-dependency leaf package with Version() and CommitSHA() accessors
2. Update -ldflags -X paths in Makefile:102 and internal/binary/crosscompile.go:64
3. Update internal/cli/root.go to import buildinfo
4. Refactor telemetry.Setup() to import buildinfo directly, removing the serviceVersion parameter

Proposed Test

// internal/buildinfo/buildinfo_test.go
func TestVersionDefaults(t *testing.T) {
    // Without ldflags injection, accessors return empty strings
    if got := Version(); got != "" {
        t.Errorf("Version() = %q, want empty", got)
    }
    if got := CommitSHA(); got != "" {
        t.Errorf("CommitSHA() = %q, want empty", got)
    }
}

// Run with: go test -ldflags "-X internal/buildinfo.version=v1.2.3
//   -X internal/buildinfo.commitSHA=abc123" ./internal/buildinfo/
func TestVersionInjected(t *testing.T) {
    // When ldflags are set, accessors return injected values
    // (This test must be run with the ldflags above)
}

// Build-level verification:
// - go vet ./... passes (no import cycles)
// - make build && ./fullsend --version reports correct version
// - Cross-compiled binaries report correct version

Context

This issue arose during the OTel SDK migration (PR #4510). The refactoring is independent of that PR and can proceed in parallel — it removes the parameter-threading workaround that PR #4510 currently uses.

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Labels: This is a maintenance/refactoring task (type/chore) with medium priority — it has clear value for code organization and directly unblocks cleaner integration for the in-flight OTel migration.

[fullsend-ai-prioritize]

RICE Priority Score: 1.8

Score breakdown

Dimension	Score	Reasoning
Reach	1	This is an internal refactoring that benefits the development team and unblocks cleaner integration for the in-flight OTel SDK migration (PR #4510). It affects any internal package that needs build metadata (telemetry, binary cross-compilation, future OTLP exporter and user-agent headers). Scored as 1 because it impacts a moderate number of internal contributors and indirectly supports a broader platform concern (observability).
Impact	1	The improvement is noticeable but not blocking — workarounds exist today (parameter threading). Moving to a leaf package removes accumulated parameter-passing, prevents import cycles, and makes future integrations (OTel resource, user-agent headers) cleaner. Scored as 1 (medium) because it's a meaningful workflow improvement for developers but has functional workarounds in place.
Confidence	0.9	Very high confidence. The issue is exceptionally well-described with specific file paths, line numbers, and a clear triage summary with 4 concrete implementation steps. The scope is tightly bounded — create one new package, update two ldflags paths, refactor one caller. There is minimal ambiguity.
Effort	0.5	This is a small, well-scoped change: create a new leaf package with two vars and two accessors, update ldflags in Makefile and crosscompile.go, update cli/root.go to import buildinfo, and refactor telemetry.Setup() signature. The triage summary provides step-by-step instructions. Scored as 0.5 (simple).

Formula: (1 x 1 x 0.9) / 0.5 = 1.8