fableplan-work-on-issuelisted

# fableplan-work-on-issue Chain fableplan → work-on-issue into one autonomous run: Fable 5 plans the implementation for a GitHub issue (plan posted to the issue), then work-on-issue implements that plan in an isolated worktree and opens a PR that closes the issue. This is **fableplan-loop with the review loop removed** — the handoff is to `work-on-issue` (single-shot, ends at the open PR) rather than `work-on-issue-loop` (which triggers `@claude` and cycles through review). Like fableplan-loop, it has no `validate-issue` step and no score gate: with no validation to produce a score, fableplan always runs. Reach for this when you already trust the issue and just want a Fable-vetted plan built and shipped as a PR, without paying for validation or driving review to convergence. ## Input Same as fableplan-loop: a GitHub issue is **required**; with nothing supplied, default to the latest open issue in the current repo. If no issue can be resolved, stop and ask — do not plan or implement against a paraphrase. ## Steps Follow **fableplan-loop steps 0 through 3** with these changes: - **Step 0 (pre-plan gate)** applies unchanged. - **Step 1 (fableplan):** instruct fableplan to use the harness suffix `fableplan-work-on-issue` in the posted comment's attribution footer. - **Step 2 (handoff):** invoke the `work-on-issue` skill instead of `work-on-issue-loop` (Skill tool, `skill: work-on-issue`). The explicit issue-number pass-through and the plan pointers (scratchpad file and pos