docs(todo-format): add the measurable-acceptance pattern for open-ended tasks

A task phrased as an absence ("find bugs until none remain," "refactor until nothing worthwhile is left," "clean it up") can't be :solo:, because it fails the verifiable-by-the-agent gate. Absence isn't falsifiable, so "done" is a judgment call, which is what :solo: forbids. This kept surfacing (the ai-launcher-hardening task is the live case) with no written recipe for fixing it.

todo-format.md gains a subsection, right after the :solo:/:quick: definitions, on converting a fuzzy goal into a measurable one: bound the surface (enumerate the units, that's the done-set), net the behavior with characterization tests, disposition every finding (fixed / filed / declined-with-reason, never "looked and it's fine"), and gate on an objective floor (static-analysis clean, suite green, coverage of the enumerated surface). The qualifying answer becomes a dispositioned report, not a claim of perfection, and the honest limit stays honest: "no visible bugs" means "every enumerated path passes its characterization set and clears the audit." Once a task carries those criteria it can carry :solo:.

work-the-backlog's keystone defer item now names open-ended goals as a specific, recognizable failure of test-writability, so a mistagged :solo: task with no writable acceptance test is deferred and routed to get criteria rather than guessed at.

start-work has the same Justify/Approach gate and wants the same pointer, but its skill lives outside rulesets, so that edit is a follow-up in its home.

1 files changed, 42 insertions, 0 deletions

diff --git a/claude-rules/todo-format.md b/claude-rules/todo-format.md
index 09b39cf..a4ffc34 100644
--- a/claude-rules/todo-format.md
+++ b/claude-rules/todo-format.md
@@ -64,6 +64,48 @@ step** in the task-review and task-audit workflows, so the run-time gate
 can trust the tag. A review or audit that skips the `:solo:`/`:quick:`
 assessment is incomplete.
 
+### Making an open-ended task measurable (so it can be `:solo:`)
+
+A task phrased as the *absence* of something — "find bugs until none are
+visible," "refactor until no worthwhile opportunities remain," "clean this
+up until it's good" — cannot be `:solo:`, because it fails the
+*verifiable-by-the-agent* gate. Absence isn't falsifiable: an agent can
+always look once more, so "done" is a judgment call, which is exactly what
+`:solo:` forbids. The fix is not to drop the task but to give it an
+objective completion criterion. Four moves convert a fuzzy goal into a
+measurable one:
+
+1. **Bound the surface.** Enumerate the concrete units the task covers (the
+   N functions, the M files, the named code paths). The done-set is that
+   list, not the platonic set of all possible defects. Every claim is made
+   against the list, so "covered" is checkable where "found everything"
+   isn't.
+2. **Net the behavior.** Bring the surface under characterization tests
+   (Normal/Boundary/Error per unit — see `testing.md`) before changing
+   anything. This is the objective floor: writing a characterization test is
+   mechanical (record what the code does, not what it should), so it scales
+   across the surface, and it doubles as the safety net that makes any
+   later refactor falsifiable.
+3. **Disposition every finding.** Run the relevant audits (a fixed
+   footgun/OWASP checklist, `/refactor`, `/review-code`) and give **every**
+   finding a verdict: fixed, filed as its own task, or declined with a
+   one-line reason. "Looked and it's fine" is not a disposition. The
+   measurement is zero undispositioned findings, not zero findings.
+4. **Gate on an objective floor.** Static analysis clean (linter,
+   type-checker, `shellcheck`), the test suite green before and after, and
+   coverage of the enumerated surface (a per-unit test checklist, or a real
+   coverage number where the tooling exists).
+
+The **qualifying answer** is then a dispositioned report — surface split
+covered/uncovered, tests before → after, static-analysis result, the audit
+matrix fully dispositioned, all green — not a claim of perfection. The
+honest limit stays honest ("no visible bugs" means "every enumerated path
+passes its characterization set and clears the audit," never "zero bugs
+exist"), but the criterion is now falsifiable, which is what lets the task
+carry `:solo:`. Write these criteria into the task body at creation or
+review time; a task that can't be given them stays non-`:solo:` until it
+can.
+
 ### Bug priority from severity × frequency (mandatory where a codebase exists)
 
 Some projects carry a codebase — source the project maintains under version