Agent Plugins 0.15.0

Eight methods from two public MIT skill collections, rewritten into the aep, ess and b10x
plugins, each with an eval case beside it.

• aep:diagnosing is a new activity skill. It builds one command that goes red on the reported
  symptom, and has already been run, before any hypothesis. Then it minimises, ranks falsifiable
  hypotheses, probes one variable at a time and writes the regression test at a seam that
  reproduces the real call pattern. The red and green runs are test_result evidence; a missing
  seam is filed as a draft story. b10x:routing reaches it.
• ess:specifying interviews before drafting a domain nobody has described
  (references/interview.md): the open decisions in numbered rounds, each with the answer the
  agent would take, facts looked up rather than asked. Headless, the questions become
  approval-records. aep:planning guardrail 7 points at it.
• The adversary and ess:testing-conformance reject a test that would still pass if every
  function it calls returned a default value, and name the five shapes that do.
• A wave verifies a green unit's claim against the base before merging: one command on both
  branches, one verdict of VERIFIED, NOT VERIFIED or INCONCLUSIVE, recorded as
  verification evidence. Only VERIFIED merges.
• The story scoper returns a Safety fact line with how far it was proved on a five-step ladder;
  the security reviewer proves that fact with a test before calling a change safe.
• The decomposer cuts stories as vertical slices and drafts a codebase-wide mechanical change as
  expand, migrate batches and contract. The design critic's fifth defect is the horizontal slice.
• On request, the adversary step runs as a cross-family panel (references/adversary-panel.md),
  one review-result per seat; with one model family it is one reviewer and says so.
• b10x:authoring-plugins carries five rules for writing what an agent reads
  (references/writing.md).
• evals/ holds 17 cases; its README recounts coverage from the subject: fields.

Sources: github.com/mattpocock/skills at c55ee46 and github.com/cursor/plugins at ecc249f,
both MIT. Each method is adapted in this repository's words; no text is copied verbatim.