Carry the generated catalogue into the served directory

[iderex]

Closes #131.

The generator has been able to build a catalogue since the disabled declaration
landed, and nothing had ever carried its output into docs/. The address an
operator pastes answered 404, and a Jellyfin server renders that as an empty
repository with no error at all.

The file is the run's output and not typed by hand

go run . publish

1 of 12 declared plugin(s) resolved with something to publish.
  1 disabled
  10 no releases

what each resolved plugin's releases came to:
  requests             1 version(s), 0 skipped, 0 stopping the run

manifest.json: wrote new bytes, carrying 1 plugin(s) and 1 version(s).

Exit status 0. What the placed file holds:

python -c "import json; d=json.load(open('docs/manifest.json',encoding='utf-8')); print(len(d),'entry'); [print(p['name'], p['guid'], p['owner'], [v['version'] for v in p['versions']]) for p in d]"
1 entry
Requests 0f9c9107-b31b-459e-81fa-6d35dac25e79 Flowfin ['0.1.0.0']

One entry and one version is the scope #65 settled on 2026-08-21. Flowfin in
the owner field is what entry 4 of #1 settled on 2026-08-22.

Both run 2026-08-23 against the tree at 8dc007d, which is origin/main at the
time this branch was cut.

The gate

go run . gate

gate examined 14 of 14 legs.
  build                            passed
  test                             passed
  format                           passed
  editorconfig                     passed
  tests-reach-nothing              passed
  no-hardcoded-names               passed
  site-fetches-nothing-outside     passed
  site-links-resolve               passed
  coverage                         passed
  site-declares-its-language       passed
  install-address-is-answered      passed
  colour-stands-off-every-surface  passed
  page-matches-the-token-file      passed
  pr-hygiene                       passed

Run 2026-08-23 with the change staged. The install-address-is-answered leg
passes because this change prints no address anywhere; it places the file the
address will answer with.

The harness did not run and was not asked for. Nothing in it gates a merge, and
the requirement that would exercise this file end to end against a real server is
needs-jellyfin, which is #54 and is open. So a green here does not say that a
Jellyfin server accepts this catalogue, and nothing in this change claims it
does.

The change is only the placed file

git diff --name-only origin/main...HEAD
docs/manifest.json

What this does not do

It does not record the address as answering. internal/address.Answered stays
empty, so no tracked file may print the address yet, and the quickstart in #55
still cannot be written. The reading that fills that list is taken after the host
has rebuilt, and it is a later step in decisions/release-procedure.md.

It does not deploy. The site is served from docs/ on the default branch by a
host this repository does not run, so the gap between this merge and the address
answering is real time that nothing here reports on.

It does not touch the served pages, sources/ or the generator.

Review

No second person has read this. That is stated rather than implied, and the
evidence above stands in place of a second reader: every claim carries the
command that produced it, and each command is one a reader can run against this
branch.