docs(skills): require campaign asset cleanup

[samchon]

Intent

Require every issue and benchmark campaign assignment to remove its disposable worktree and assigned mutable assets, including Go temporary caches, before completion.

Scope

• Record and remove every assigned campaign mutable root before removing a finished issue-campaign worktree.
• Apply the same completion rule to verifier and mutation worktrees.
• Define benchmark-campaign cleanup for disposable worktrees, mutable roots, Go temporary assets, and any associated disposable local branch.

Deferred

This documentation-only pull request does not make #2262 ready, alter its prospective gate, or merge any campaign pull request.

Local verification

• Re-read the complete .agents/skills/issue-campaign/development.md and .agents/skills/benchmark/SKILL.md contexts after editing.
• git diff --check
• git show --check --stat 22c6c8ca67ffd67e496938c64af2ec1de3c6b907

Campaign Actions are deliberately cancelled; the exact-SHA cancellation records are maintained in the campaign knowledge base.

[samchon]

Self-review opening for 22c6c8ca67ffd67e496938c64af2ec1de3c6b907.

I will review the complete base-to-head diff and both full SKILL contexts. The boundary check covers an isolated mutable root with no worktree, detached worktrees with no topic branch, disposable topic branches, Go temporary assets, retained evidence, and the required order of removal and verification. I will report remediation before changing anything; this PR remains draft and is not a merge action.

[samchon]

Self-review complete: no remediation.

Reviewed immutable master...22c6c8ca67ffd67e496938c64af2ec1de3c6b907 (two SKILL files only) and re-read both complete documents. The cleanup rule preserves compact evidence before destructive removal, removes every assigned GOCACHE, GOTMPDIR, TTSC_CACHE_DIR, generated/consumer/staging root, then proves their absence. It covers verifier and mutation worktrees.

Boundary results:

• An isolated measurement root without a worktree removes and verifies its roots; worktree removal is explicitly conditional.
• A detached worktree has no associated local topic branch to delete.
• A worktree with an associated disposable topic branch removes that branch only after worktree removal and pruning.

git diff --check master...HEAD passed. No product, package, generated artifact, consumer, or workflow surface changed; no pnpm format or build/test applies to this active-campaign Markdown-only rule change. PR remains draft; no merge action was taken.