chore(skills): Add linear-project-status skill (#21214)

## Summary

Adds a new agent skill, `linear-project-status`, that audits a Linear
project's health and produces a Green/Yellow/Red status summary aimed at
a project lead or engineering manager. Designed to be run roughly
weekly.

The skill checks:

- Status-update cadence
- Project lead presence (binary) and lead engagement (whether the lead
is actually doing the work)
- Target date presence, realism vs. open scope, and stability (push-out
history per status updates)
- Per-issue staleness and a project-level recent-activity pulse (last 7
days)
- Milestone health
- Scope stability (issue additions)
- External blockers surfaced from status updates and comments

Triggered via `/linear-project-status
<linear-project-url-or-id-or-slug>`.

## Example

Example report for `/linear-project-status
https://linear.app/getsentry/project/js-migrate-senddefaultpii-to-new-datacollection-spec-560a172dc579/overview`:

# Project status: [JS]: Migrate `sendDefaultPii` to new `DataCollection`
spec

**Verdict:** 🟢 Green — On track. Strong velocity (9 of 26 issues done, 5
in flight just one week into execution), Foundation milestone hit on
time, fresh "onTrack" update posted today, and the lead/implementer
split (Sigrid coordinates, Charly executes) is working. Watch the
Migration milestone's tight Jun 8 deadline.

**Project:** [\[JS\]: Migrate `sendDefaultPii` to new `DataCollection`
spec](https://linear.app/getsentry/project/js-migrate-senddefaultpii-to-new-datacollection-spec-560a172dc579)
· **Lead:** Sigrid Huemer · **Target:** 2026-06-12 (15 days away) ·
**Issues:** 17/26 open (9 done; 5 in flight, 12 in backlog)

## Top concerns

- **Migration milestone (Jun 8, 11 days away) is the critical path.**
Currently at 13% with 5 issues in flight (cloudflare, node-core, nextjs,
browser, core) and several still in backlog (Node AI, core AI, remix,
bun/deno, nitro/nuxt/sveltekit/astro/vercel-edge). Cleanup & Tests (Jun
10) and Docs (Jun 11) both at 0% are gated on this. If Migration slips,
the project's Jun 12 target slips with it.
- **Latest status update already telegraphs a 1-week milestone slip.**
Sigrid's update today says the Migration milestone was moved a week
because of conference attendance + illness. That's an honest
acknowledgement but it's eaten the project's buffer — there's no slack
left between Migration finishing and the project target.
- **Two issues are explicitly v11 (out of scope for this Jun 12
target):** JS-2580 ("httpclient: Use granular dataCollection settings
instead of sendDefaultPii gate") and JS-2509 ("Deprecate
`sendDefaultPii`, resolve remaining TODOs") are tagged for the next
major. They count against the open-issue total but shouldn't gate the
project's Jun 12 ship — consider moving them to a follow-up project to
clean up the count.
- **Lead is engaged in coordination, not execution.** Sigrid is the lead
but only assigned to 2 of 26 issues (1 done bridge issue, 1 backlog
parent). Charly is doing the vast majority of the work. That's a
legitimate two-person pattern, but worth being explicit about it — if
it's a deliberate split, document it; if it's drift, rebalance.
- **The big backlog of integration migrations (remix, bun/deno,
nitro/nuxt/sveltekit/astro/vercel-edge, Node AI, core AI) hasn't been
started yet.** Five issues in flight already; another five integration
migrations are still Backlog. With 11 days to the Migration milestone,
the queue needs to start clearing this week.

## Dimension breakdown

| Dimension | Verdict | Notes |
| ---------------- | ------- |
--------------------------------------------------------------------------------------------------------------
|
| Status updates | 🟢 | First update posted today (2026-05-28), health
"onTrack". Project only formally started 7 days ago. |
| Lead | 🟢 | Sigrid Huemer is set. |
| Lead engagement | 🟡 | Sigrid assigned to 2 of 26 issues. Plays
coordination/lead role; Charly does most implementation. Valid pattern
but worth making explicit. |
| Target date | 🟡 | 2026-06-12, 15 days away. 17/26 (65%) open. Tight
but lead self-reports onTrack; Foundation hit on time. |
| Target stability | 🟢 | Project target unchanged. (1 internal milestone
moved a week per today's update, but project target intact.) |
| Issue staleness | 🟢 | All 5 started issues updated within 6–7 days.
Backlogs mostly created 13 days ago; only JS-2061 is 23d stale. |
| Recent activity | 🟢 | 5 completions in last 7 days (Supabase, tRPC,
logs, metrics, request data) + 5 in flight. Strong cadence. |
| Milestones | 🟢 | Foundation hit on time (May 20, 100%). Migration (Jun
8), Cleanup (Jun 10), Docs (Jun 11) future. Breaking Changes is
intentionally v11. |
| Scope stability | 🟢 | 1 new issue (JS-2580) added since start, and
that's a v11 follow-up. Scope is locked. |

## Recommended next steps

1. **Prioritize the next 3–5 Migration milestone issues** that should
start this week to clear the integration backlog: pick the smallest
first (e.g., JS-2507 bun/deno, JS-2508
nitro/nuxt/sveltekit/astro/vercel-edge) to keep momentum visible.
2. **Move JS-2580 and JS-2509 out of this project** (or at least off the
Migration milestone) — both are explicitly v11. They inflate the
open-issue count for a Jun 12-targeted project.
3. **Lock in a weekly cadence now that the project is in execution.**
Today's update is excellent; a Mon/Tue update next week is what tells
stakeholders whether Migration is on its new (slipped) Jun 8 target.
4. **Decide on the lead/implementer split explicitly.** If Sigrid leads
and Charly implements by design, write that into the project description
so it's not read as "lead is absent." If both are meant to implement,
rebalance the next batch of assignments.
5. **Start Cleanup & Tests + Docs scoping in parallel** with the last
Migration items. With Jun 10/11 deadlines, those milestones can't wait
until Jun 8 — pull one Docs ticket (e.g., JS-2511 user docs) forward
this week.

---

_Data as of 2026-05-28. Run weekly to track trend._

---------

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>