project-platform-diagnoselisted

# Project Platform Diagnose This overlay can stand alone for environment-only triage. Add matching language or discipline guidance when the diagnosis reaches source code or a specialized implementation boundary. ## When to use The problem differs by operating system, architecture, terminal, shell, CI, container, headless mode, installed runtime, service environment, or another platform fact. ## Not for Do not use this as primary for a reproducible logic bug (use the matching principle skill and add `project-core-dev` only when repository-specific completion evidence is not concrete), a known config-contract defect (`project-config-and-tests`), Playwright harness or browser installation repair (`setup-playwright`), vendored dependency ownership (`project-vendor-boundary`), or release artifact layout (`project-release-maintainer`). Start here only while the environment remains a plausible cause, then hand off when the failure is isolated. ## Diagnostic Workflow 1. Inspect the failing command's side effects before rerunning it. Reproduce it within existing authority, using an isolated or check-only variant when needed, and capture exit status and relevant output. A failed install, migration, or deployment is not automatically safe to repeat. Separate build or install failures from startup and runtime failures. 2. Record only relevant non-secret facts: OS, architecture, runtime and tool versions, shell or terminal mode, local versus CI or container, filesyst