validate-fableplan-loop

# validate-fableplan-loop Chain validate-issue → (conditional) update issue → (conditional) fableplan → work-on-issue-loop into one autonomous run: your session model validates the issue against the code, the main agent fixes the issue description if needed, Fable 5 plans the implementation for non-trivial issues (plan posted to the issue), and work-on-issue-loop implements the plan and drives the PR through review to convergence. This is **validate-issue-loop with a Fable 5 planning phase inserted before implementation** — identical to fable-validate-loop except validation runs through the plain `validate-issue` (your session model) instead of a Fable 5 subagent. Only the *planning* is delegated to Fable 5, and only when the issue is complex enough to warrant it. Reach for this over fable-validate-loop when you want cheaper, session-model validation but still want a Fable-vetted plan for the harder issues. **Do not skip or reorder the chain.** Validation gates planning (a plan built on refuted claims is wrong), and the plan gates implementation (that's the point of routing through fableplan). The only sanctioned skip is the step-4 Capability gate (Capability < 2 / score < 50 bypasses fableplan). Every other step of each skill still runs; only the "wait for the user's reply" moments are replaced by the decision rules below. ## Input Same defaults as validate-issue: issue URL, `#<N>` / `<N>` / `owner/repo#N`, or nothing (defaults to the latest open issue in the current re...