chore(skills): Reframe linear-project-status as a project review, not a people review

Sharpens the linear-project-status skill so it's clearly a tool for project leads
auditing their own projects, not a performance review of any individual.

Key changes:

- Add an "Audience and intent" section: the audience is the project lead, the
  verdict is a signal (not a grade), and the audit can't see PTO / competing
  priorities / work outside Linear — recommendations should target the project's
  process, not the people.
- Lead engagement (dim 2b) reframed around whether the lead is finding time to
  engage with the project. Explicitly recognizes two healthy shapes: implementer
  (assigned to issues) and orchestrator (drives via updates / comments /
  milestones). A `warn` is not a critique.
- Target date stability (dim 4) now weighs both push count and quality of
  explanation. Well-documented pushes (illness, scope change, dependency slip)
  earn `warn`; vague or undocumented pushes earn `bad`.
- Target date presence/realism (dim 3) adds a special-case block for "target
  date is today or past, project not Completed" — common enough to deserve
  explicit handling.
- Milestone health (dim 6) adds a distinct "tracking-hygiene gap" verdict for
  past-due milestones where the work clearly shipped but wasn't marked complete
  — the fix is cleanup, not a delivery concern.
- Status update cadence (dim 1) now reads trajectory across the last ~6 weeks.
  A long silence followed by a fresh update is `warn` with positive framing
  (recognize the correction). Steady recent rhythm is `ok` even if there was an
  old gap further back.
- Scope stability (dim 7) carves out planned decomposition: new issues sharing
  a common `parentId` are a structural breakdown of existing scope, not drift —
  never flag them.
- Common failure modes: "Reviewing people instead of the project" added as the
  top entry.

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

Author: mydea