Document permission requirement: full loop needs repo Triage/Write

Add an explicit 'Permissions: who can run the full loop' section to SKILL.md so users know up-front which mode applies to them. Repo collaborators with Triage/Write get hands-off multi-round autopilot. External PR authors get single-iteration mode plus a documented manual re-trigger (UI 🔄 or push a substantive commit). The limitation is GitHub's, not ours — verified that requestReviewsByLogin is the only public API for bot reviewers and it requires write permission.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: yeelam-gordon

skills/copilot-pr-autopilot/SKILL.md

@@ -45,6 +45,17 @@ installed and authenticated (see Prerequisites).
   fails (the script can't reliably tell "Copilot disabled" from
   "Copilot enabled but not yet triggered" from API state alone).
 
+### Permissions: who can run the full loop
+
+The full multi-round autopilot (steps 1 → 9 → 1) needs **Triage or Write** permission on the target repo, because GitHub's only public API for adding the Copilot bot as a reviewer (`requestReviewsByLogin`) is gated on that permission. Verified against the public REST + GraphQL surface in this PR's commit history — there is no public-API path for bot reviewers without write permission.
+
+| You are… | What works |
+|---|---|
+| **Repo collaborator with Triage / Write** | Full loop: `01` triggers Copilot, `02` waits, `04`–`08` triage / fix / reply, loop back to `01`. Hands-off. |
+| **External PR author (no write permission)** | `01` will throw a clear actionable error. Use `-SingleIteration` mode: address all current findings in one pass, then either click the UI 🔄 next to Copilot, **or** push a substantive commit (the `synchronize` event auto-triggers Copilot on most repos). Then re-run `02` to verify. |
+
+In single-iteration mode the loop's convergence boolean is `Converged: true` iff `OpenThreadsAwaitingReply == 0` (the agent's side is done). The maintainer-side re-trigger then drives any additional rounds.
+
 Every script dot-sources [scripts/_lib.ps1](scripts/_lib.ps1) which
 runs `Assert-GhReady` on load: if `gh` is missing OR `gh auth status`
 fails, the script halts **before any work** with a single actionable