Add a scheduled cross-repo Weaver Stack integration smoke test

Summary

Add a scheduled (weekly, non-gating) CI workflow that exercises contextweaver against its sibling repositories end-to-end — an agent-kernel Frame ingested into the context engine, a routed/built result, and a telemetry/handoff payload consumed by ChainWeaver's contract — so cross-repo drift in the Weaver Stack surfaces as a red scheduled run instead of an adopter bug report.

Why this matters

The stack's value proposition is that the sibling projects compose: weaver-spec defines contracts, agent-kernel produces Frames, contextweaver compiles context, ChainWeaver consumes telemetry. Today only the schema layer is verified (conformance gate); no executable test proves the repos still work together at HEAD. Cross-repo integration is exactly where independently evolving codebases drift silently — and where the existing boundary work (#352) and telemetry contract (#382) need an enforcement mechanism.

Current evidence

• .github/workflows/ci.yml:111 — the "Weaver-spec conformance" step validates against schemas (scripts/weaver_spec_conformance.py), with #469 (open) pinning it to a tagged schema version — schema-level only, no sibling code executed.
• Open #352 documents the Frame-boundary seam with agent-kernel ("contextweaver receives Frames, not raw output"; I-05 only partially satisfied) and open #382 defines the telemetry handoff contract to ChainWeaver — both are contracts an executable smoke would pin.
• The repo already has the cron-workflow pattern to copy: weekly scorecard and deps-latest workflows exist (.github/workflows/deps-latest-weekly.yml).
• examples/architectures/contextweaver_to_chainweaver/ exists — a natural seed scenario for the smoke.

External context

Multi-repo ecosystems commonly run scheduled "canary" integration builds at HEAD (non-gating) to separate integration drift from per-repo PR signal.

Proposed implementation

1. Define the minimal smoke scenario with the maintainer: construct a Frame per weaver-spec (or import agent-kernel's producer), ingest via the Frame adapter path, build_sync a pack, route a query, emit the ChainWeaver-bound telemetry/handoff payload, and validate it against ChainWeaver's consumer (or its published schema if installing ChainWeaver is too heavy for v1).
2. New workflow weaver-stack-smoke.yml: weekly cron + manual dispatch; installs sibling repos from GitHub at default-branch HEAD; runs the scenario; never gates PRs.
3. Failure routing: scheduled failure opens/updates a pinned issue (same pattern as other cron jobs if one exists, else simple gh issue step) identifying which seam broke (install, Frame shape, telemetry shape).
4. Start with the contextweaver→ChainWeaver example as the seed; add the agent-kernel Frame leg second.

AI-agent execution notes

• Inspect first: scripts/weaver_spec_conformance.py (what is already covered — do not duplicate it), examples/architectures/contextweaver_to_chainweaver/, docs/weaver_spec_mapping.md, sibling repos' install story (pip install git+... viability), deps-latest-weekly.yml as the workflow template.
• Keep it smoke-sized: one scenario, minutes not hours; the goal is drift detection, not coverage.
• Non-gating is a design decision, not an accident — sibling HEAD breakage must never block contextweaver PRs.
• Failure modes: sibling repo install breakage (report distinctly from contract breakage); version skew between weaver-spec tag (per #469) and sibling HEADs — record all versions in the run summary.

Acceptance criteria

• A scheduled workflow installs at least one sibling repo and runs the cross-repo scenario green at current HEADs.
• A deliberately broken contract fixture (tested via workflow-dispatch on a branch) produces a failure that names the seam.
• Run summary records the exact sibling commits/versions exercised.
• PR CI duration and gating behavior are unchanged.

Test plan

The workflow is the test; verify via manual dispatch on the PR branch; one local runner script (documented) so maintainers can reproduce failures without CI.

Documentation plan

docs/weaver_spec_mapping.md or ecosystem docs note describing the smoke and what it guarantees; AGENTS/agent-context workflow docs entry; CHANGELOG.

Migration and compatibility notes

Not expected to require migration; CI-only addition.

Risks and tradeoffs

Scheduled-job neglect is the classic failure (mitigate with the auto-filed issue on failure); sibling repos' instability could make the signal noisy (start with the most stable seam — ChainWeaver schema validation — before live-code legs); maintenance falls on one maintainer across repos (keep the scenario tiny). Alternative — schema conformance only — already exists and demonstrably cannot catch behavioral drift.

Suggested labels

testing, ecosystem, integrations, reliability

Start with .github/workflows/deps-latest-weekly.yml, scripts/weaver_spec_conformance.py, and examples/architectures/contextweaver_to_chainweaver/; inspect the sibling repositories' installation instructions and docs/weaver_spec_mapping.md. Reproduce the seed scenario locally before designing the scheduled workflow and manual dispatch path. Done means the workflow runs non-gating at current sibling HEADs, records exact versions, reports the failing seam, and has the documented local reproduction path.