feat(lint): broken-link check + lint before push; drop scan-stage tool

[sVIKs]

What

Reworked per maintainer feedback: pre-deploy validation should be lint, run right before push — not a separate stage-scan tool. So this PR no longer adds a scan-stage tool; instead it folds the one salvageable check into lint-process and makes push-process lint automatically.

• lint-process gains broken node-link detection — a logic to_node_id/err_node_id/go_to/goto, or a semaphor to_node_id/esc_node_id, pointing at a static 24-hex node id that is absent from the process. The server rejects such a deploy ("referenced node does not exist"); now caught offline, before the round-trip. Dynamic {{...}}/@alias targets resolve at deploy and are left alone.
• push-process runs lint before deploying and blocks on issues that would break the deploy or its callers: broken links, old-format nodes, RPC paths without reply, nodes missing a default go, sub-30s timers, literal reply values. Advisory findings (noop, unused set_param, orphans, passthrough, shared clusters) are shown but do not block. force=true overrides.
• The standalone stage-export scanner is removed — the corezoid-stage-scan skill and its scan_stage.py are gone. Its per-process check moved into lint (above); the cross-process conv_id/api_get_task reference checks are left to the server, which already rejects bad references on deploy — no point duplicating them offline (they'd need to fetch the whole stage anyway).

Net: 172 insertions / 400 deletions — the change removes more than it adds.

Verified

• go build, go vet, go test -race ./... green; TestToolRegistryMatchesREADME green.
• New unit tests for the broken-link check (dangling logic/semaphor targets flagged; valid and dynamic targets not).
• End-to-end via the CLI binary: a process with a dangling err_node_id reports === BROKEN NODE LINKS (1) === with a precise message.
• Skill removal is reference-clean: README, POWER.md (skill count + capability), the main skill's list, install-kiro.sh, and public/ discovery artifacts all updated; no dangling references remain.

🤖 Generated with Claude Code

[gh-corezoid]

AI Review

Ports the corezoid-stage-scan skill's Python validator (scan_stage.py) into a new scan-stage MCP tool implemented in Go inside convctl, preserving all five defect classes and report semantics while adding zip-slip protection and duplicate-obj_id resilience; the Python script is deleted and the checks now run as ordinary Go tests.

Checklist

Check	Result
U1 — Conventional commit format	✅ pass
U2 — No leaked credentials	✅ pass
U3 — No merge commits	✅ pass
U4 — PR targets correct base branch (main)	✅ pass
U5 — Build & tests (Go)	✅ pass
U6 — Architectural & design consequences	⚠️ warning (see below)
C1 — Manifest files version-synced	⬜ skip (no manifest files changed)
C2 — Node IDs in .conv.json valid	⬜ skip (no .conv.json files changed)
C3 — No hardcoded env values in .conv.json	⬜ skip (no .conv.json files changed)
C4 — extra fields have extra_type	⬜ skip (no .conv.json files changed)
C5 — README updated for new skills	✅ pass

U5 detail: go build ./..., go vet ./..., and go test ./... -count=1 all exit 0 on the PR branch. The same test suite exits 0 on the base commit (2107719) — no regressions introduced.

Issues found

[warning] U6 — CLI exit-code contract changed for existing CI consumers

The Python scan_stage.py exited with 1 when any blocker was found and 0 when clean — a standard CI gate. The Go server CLI exit code now reflects tool-level errors only (bad path, unreadable ZIP), never the scan verdict. The SKILL.md has been updated to document the grep 'No blockers found.' workaround, but any pipeline that currently runs:

python3 .../scan_stage.py stage.zip --quiet

and gates on the exit code will silently break after this change: it will always exit 0 regardless of findings, because the CI step will likely be updated to call the Go CLI without adding the grep gate. Concrete failure scenario: a broken stage is merged because the old exit 1 path no longer fires and the pipeline appears green.

Suggested fix: Add a one-line migration note near the top of SKILL.md (e.g. "⚠ If you previously gated CI on the Python exit code, replace with | grep -q 'No blockers found.' — see the CI recipe below"). Alternatively, the CLI wrapper could re-add a non-zero exit when the report contains BLOCKERS FOUND (grep of its own output), but that is a separate decision.

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This review was generated automatically. A human maintainer should still make the merge decision.

[salimovartem]

Stepping back from the code — I'm not convinced this tool belongs in the plugin right now.

The plugin has no whole-stage operation: push-process pushes one .conv.json at a time, and there is no stage-merge or stage-deploy tool here. All five checks in scan-stage are aimed at exactly that missing workflow ("pre-merge / pre-deploy validator" per SKILL.md:4). In the actual dev cycle we have — edit a process, push it — the platform itself will return the same "Only active process can be used" / broken-link errors at push time. scan-stage predicts errors for a merge that this plugin cannot perform.

Its real audience is support/integration work (auditing exported stage zips) and Corezoid-UI stage merges — both orthogonal to what the plugin does today.

Two ways to make the work land without carrying dead weight:

1. Move the per-file checks — [1b] empty process and [2a] intra-process broken node links (to_node_id / err_node_id / go_to) — into lint-process. They need no export and no cross-file view; devs would catch them on every push-process for free. plugins/corezoid/mcp-server/lint.go:105 is the natural home.
2. Keep scan-stage out of the plugin until there is a whole-stage operation to anchor it (stage export/merge/deploy). At that point the remaining [1] / [2b] / [2c] checks fit naturally as its pre-flight; today they have nothing to gate.

Suggest deferring the merge and doing (1) as a smaller PR against lint-process.

[sVIKs]

Reworked this PR per the feedback that validation belongs in lint-before-push, not a separate tool.

Pivot: dropped the scan-stage tool entirely (and the corezoid-stage-scan skill + scan_stage.py). Instead:

• the salvageable per-process check (broken node links) is now part of lint-process;
• push-process runs lint-process before deploying and blocks on deploy-breaking findings (force=true overrides);
• the cross-process conv_id/api_get_task checks are not reimplemented offline — the server already rejects bad references on deploy, and pre-checking them would mean fetching the whole stage to duplicate the server's own validation.

Force-pushed; title and description updated. Gates green (build/vet/test -race, registry↔README).

[gh-corezoid]

AI Review

Re-review after synchronize: reworks the PR from a scan-stage MCP tool into two orthogonal improvements — broken-link detection added to lint-process and a pre-push lint gate wired into push-process; the Python corezoid-stage-scan skill and its scan_stage.py are removed entirely.

Checklist

Check	Result
U1 — Conventional commit format	✅ pass
U2 — No leaked credentials	✅ pass
U3 — No merge commits	✅ pass
U4 — PR targets correct base branch (main)	✅ pass
U5 — Build & tests (Go)	✅ pass
U6 — Architectural & design consequences	⚠️ warning (see below)
C1 — Manifest files version-synced	⬜ skip (no manifest files changed)
C2 — Node IDs in .conv.json valid	⬜ skip (no .conv.json files changed)
C3 — No hardcoded env values in .conv.json	⬜ skip
C4 — extra fields have extra_type	⬜ skip
C5 — README updated for new skills	✅ pass

U5 detail: go build ./... exits 0 on the PR branch (commit f67ab50). go test ./... -count=1 exits 0 on the PR branch (ok convctl 45.2s). Same suite exits 0 on base main (ok convctl 50.7s) — no regressions introduced. New TestBrokenLinks_* tests all pass.

Fixed since last review ✅

• Previous U6 (CLI exit-code contract) — the previous review flagged that scan_stage.py exited 1 on blockers while the Go path did not, breaking CI pipelines that gated on that exit code. scan_stage.py and the entire corezoid-stage-scan skill are now deleted; the concern no longer applies.

Issues found

[warning] U6 — Advisory lint findings are silently discarded by push-process when no hard findings exist

The tool description in tools_registry.go says:

"advisory findings are shown but do not block"

The PR body also says: "advisory findings are shown but do not block."

But the handlePushProcess implementation in mcp_handlers_process.go only returns lint output in the early-return blocking path:

if hard > 0 && !force {
    return "Push blocked: ...\n\n" + FormatLintResult(lintRes), true  // shown + blocked
}
if hard > 0 && force {
    fmt.Fprintf(os.Stderr, "[lint] %d blocking issue(s) overridden\n", hard)
    // FormatLintResult still not returned to the caller
}
// hard == 0 → falls through silently; advisory-only findings are never shown

When a process has only advisory findings and no hard findings, the push succeeds with zero lint output. The user or AI agent never sees the advisory issues.

Concrete failure scenario: an agent pushes a process that has 3 noop conditions and an orphaned node. All go silently into production. Later a standalone lint-process run surfaces issues the agent never saw — the "shown but do not block" promise in the tool description was never fulfilled during the push.

Suggested fix (two options):

1. Surface advisory findings in the push result when the push succeeds — append them as a trailing note rather than blocking.

2. If silent behavior is intentional, update the tool description to drop "are shown" — a one-line fix in tools_registry.go that brings the spec in line with the implementation.

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This review was generated automatically. A human maintainer should still make the merge decision.