external-campaign-triagelisted

# External Campaign Triage Use this for a campaign tracker repo (e.g. `open-source-tracker`) running many concurrent candidate issues/PRs across third-party repos we don't own. `ai-agent-pr-metadata`'s `picked by agent` / `agent:<model>-<effort>-<role>` label convention only works on repos we own or collaborate on; it cannot be applied to someone else's issue or PR. This skill defines the state machine and metadata that replace it: JSON records in the tracker repo, not upstream labels. ## State machine Each candidate moves through these states, recorded in the tracker, never skipped backward: `scouted` → `viability_checked` → `claimed` → `implementing` → `in_review` → `merged` | `abandoned` | `stalled_awaiting_maintainer` | `silenced` - `scouted`: a candidate issue/repo identified, not yet vetted. - `viability_checked`: `external-pr-viability` ran; only proceed past this state if it passed. - `claimed`: an agent has started work. Check the tracker for an existing `claimed`/`implementing`/`in_review` record on this candidate before starting — the tracker file is the source of truth for "already picked" since no GitHub label exists to signal it. - `implementing`: code, tests, and PR draft in progress, following `subagent-pipeline` roles. - `in_review`: PR opened (`external-pr-style` for the description) and awaiting maintainer response. - `stalled_awaiting_maintainer`: reached only through the Maintainer Follow-Up Guardrail below. Terminal until a maintainer responds; neve