development/ had restated the actionables that CONTRIBUTING.md owns: the
branching step list, the script prefix list, the feedback-tier rule of thumb,
the commit convention and the type-driven test loop. Those now live only in
CONTRIBUTING.md; development/ keeps the decision blocks and links to the rule.
development/README.md, CONTRIBUTING.md and AGENTS.md state the 'write each fact
once' principle explicitly.
AGENTS.md and CONTRIBUTING.md now state that a decision, its rejected
alternatives and its known issues belong in development/<category>.md, that the
actionable rule stays in CONTRIBUTING.md, and that both change in the same
commit. development/README.md names library.md in the category list and spells
out that the sync runs in both directions.
Category files under development/ replace the decision prose that was
scattered through README.md and CONTRIBUTING.md. Each decision is a block with
Decision (YYYY-MM) / Why / Rejected / Known issue; the new library.md records
the public API contract and its limitations. AGENTS.md and backlog.tasks now
point at the new home.
tmu