feat(cli): prophet spine validate gate command

[mdheller]

Summary

• Adds prophet spine validate — runs all five private-preview spine gate checks sequentially (prophet-mesh, agent-registry, model-router, agentplane, memory-mesh) and reports a structured JSON result with per-step status
• Adds prophet spine gate <repo> — runs a single repo's gate in isolation
• Adds prophet spine list — lists all registered gates and their steps
• Registers newSpineCmd() in root.go
• Extends Makefile validate target to smoke-test spine list and spine gate --help at build time

The implementation follows the existing delegateOrFallback / runDelegate patterns in fabric_fallback.go. Each gate resolves the repo directory via localRepoRoot() (respects PROPHET_DEV_ROOT env var), runs make validate (and make test where applicable), and captures stdout/stderr + elapsed ms per step.

Gate configuration

Repo	Steps
prophet-mesh	make validate, make test
agent-registry	make validate, make test
model-router	make validate, make test
agentplane	make validate, make test
memory-mesh	make validate-prophet-mesh-scope-mirror

Test plan

• go build succeeds (confirmed locally — go vet clean)
• bin/prophet spine list emits JSON gate list
• bin/prophet spine gate prophet-mesh runs make validate + make test in ~/dev/prophet-mesh
• bin/prophet spine validate runs all five gates in sequence
• bin/prophet spine validate --repo agent-registry runs single-gate shorthand
• make validate passes build-time smoke checks

Note: internal/cmd test binary crash (missing LC_UUID) is pre-existing on main (dyld issue in this macOS environment), not introduced by this PR.

🤖 Generated with Claude Code

[chatgpt-codex-connector]

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[chatgpt-codex-connector]

Return a non-zero error when validation fails

When any repo gate fails, allPassed is set to false and the JSON status becomes failed, but this path still returns only emit(...); if the output is written successfully, Cobra sees a nil error and prophet spine validate exits 0. In any CI or release script that uses this validation gate, failed make validate/make test checks would be treated as success, so the command needs to return an error after emitting a failed result.

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[chatgpt-codex-connector]

Fail the single-repo gate on failed steps

For a known repo, runGate can return status: "failed" when one of its make steps fails, but runSpineGate still returns nil here as long as the JSON output succeeds. That means prophet spine gate prophet-mesh exits 0 despite a failed gate, which defeats callers that rely on this command to block on a single repo's validation result.

Useful? React with 👍 / 👎.