Bumps the version to 0.9.0 and assembles the three changelog.d fragments
into a dated 0.9.0 section, deleting them in the same commit.

Minor rather than patch: the fragments carry `### Added` bullets that
name new public surface. The storage-adapter behaviour gains three
optional input-log callbacks and `Runs.inputs/2` reads the log back,
`Storage.Ecto` implements them through migration V05 on Postgres and
SQLite, and two new telemetry events surface the per-child answers and
the settlement decision. Nothing is removed and no existing signature
changes, so no major - the two `### Changed` bullets alter what an
existing callback returns off Postgres and what `child.answered` reports
for a fan-out, both behaviour rather than shape.

The README install pin moves from `~> 0.8` to `~> 0.9`: it carries the
major/minor form with the patch component dropped, and a minor moves it.

The lead paragraph is the only prose written at release time and names
the input log, the settlement telemetry and the honest metadata refusal;
every bullet is carried over byte for byte, grouped Added then Changed.
The section date is the local date of this machine (`date +%F`), per the
fleet's 2026-09-06 convention.

CLAUDE.md's released-version line is left alone: it states what is
published, which stays true until the operator publishes.

No tag and no publish: those stay with the operator.

Refs: sp-hw6