feature-flag-retirerlisted

Feature flags are born temporary and die permanent. Once a flag is fully rolled out or quietly abandoned, the `if (flag)` it guards is just branching debt — two code paths where one is now unreachable. This skill retires a flag for real: it pins down which branch actually won, finds *every* reference (not just the obvious helper call), collapses each conditional to the winner, and deletes the loser along with any code only the dead branch reached — one flag at a time, with tests green after each. ## When to use this skill - A flag meant to last a sprint has been at 100% (or 0%) for months and still litters the code with conditionals. - Flag checks have multiplied — nested `if (flagA && !flagB)` paths nobody can reason about — and you want to pay down the debt. - You're running a flag-debt cleanup and need each removal to be independently reviewable and revertible. > [!WARNING] > Verify the flag's *decided* final state before you collapse anything. "Currently 100%" is not "permanently on" — a flag mid-rollout, a kill-switch, or an experiment still gathering data must NOT be retired. Deleting the live branch ships or kills a feature: that's a production incident, not a cleanup. Confirm from the flag system/config AND a human owner that the decision is final, and which branch won. ## Instructions 1. **Pin down the decided final state — not the current value.** For the flag, answer one question: is it *permanently on* (fully rolled out, winner = enabled branch) or *abandoned