docs(15.9): document every fess-setup command and fix the ZIP first-run steps

[marevol]

Found while verifying 15.9.0. A reader who follows the 15.9 install guide for the ZIP does not reach a running Fess, and most of bin/fess-setup is not documented anywhere.

Requires codelibs/fess#3447 and codelibs/fess#3448; merge those first. The parts that describe their behaviour are marked [#3447] and [#3448] below; everything else is already true on main. Can be merged independently of #536: in install/upgrade.rst this only adds a paragraph inside the "embedded OpenSearch removed" section, and the two branches merge without conflicts.

What is wrong in the 15.9 tree

• install/install-linux.rst tells readers to add the plugins to an existing OpenSearch with bin/fess-setup install plugins --opensearch-home .... That exits 1 with error: unknown component: plugins; since feat(setup): install and remove Fess plugins from the command line fess#3413 the command is install opensearch-plugins. The same line is in all seven languages.
• The fess-setup tip says the command performs the manual steps, but install opensearch wrote only configsync.config_path. The OpenSearch it installed kept the security plugin enabled and did not start (No SSL configuration found), and Fess could not create its indices because FESS_DICTIONARY_PATH stayed unset. fix(setup): make the OpenSearch installed by fess-setup usable without manual edits fess#3447 adds plugins.security.disabled: true and lets bin/fess.in.sh / bin\fess.in.bat find the dictionary directory, so the tip and "Configure Fess" have to say what is now automatic and when the variable still has to be set by hand.
• The "Before (default state)" excerpt of bin/fess.in.sh is the 15.8 file, with a commented-out SEARCH_ENGINE_HTTP_URL to uncomment. In 15.9 that line is active: SEARCH_ENGINE_HTTP_URL=${SEARCH_ENGINE_HTTP_URL:-http://localhost:9200}. The Windows excerpt still names %SEARCH_ENGINE_HOME%, which 15.9 removed.
• Seven of the ten fess-setup commands appear nowhere in the documentation: check, install opensearch-plugins, list, list installed, list plugins, remove plugin and upgrade plugins.
• install/install.rst sends macOS ZIP users to the Linux page, which does not say that install opensearch exits with an error on macOS because OpenSearch publishes no macOS build.
• Nothing says OpenSearch must run as a regular user. A start as root is refused (can not run opensearch as root) but leaves config/opensearch.keystore owned by root, so the next start as a regular user fails with AccessDeniedException.
• The upgrade note on the removed embedded OpenSearch names SEARCH_ENGINE_HTTP_URL but not FESS_DICTIONARY_PATH.
• ko only: admin/fileconfig-guide.rst does not say how to install fess-storage-s3 and fess-storage-gcs, and admin/storage-guide.rst does not mention fess-storage-gcs.

Changes

All in the 15.9 tree, in all seven languages unless noted.

• install/fess-setup.rst (new, added to the install toctree): a reference for every command, taken from the usage text and option parsing in FessSetup.java, Diagnostics.java and fess-setup.properties. It covers the exit codes (0, 1, 2); install opensearch, including what it appends to opensearch.yml, when it leaves a setting out, re-running it, --dest, --version, the refusal on macOS and a warning about plugins.security.disabled: true [#3447]; install opensearch-plugins; install nodejs; install plugin, list plugins, list installed, upgrade plugins, remove plugin and --repository; list; and check, including what it checks, where the engine URL comes from, --playwright and its exit code.
• install/install-linux.rst, ZIP section:
  • A note that OpenSearch, and bin/fess-setup with it, has to run as a regular user.
  • The tip names install opensearch-plugins, says what install opensearch adds to opensearch.yml, that the Fess ZIP must be extracted first, and that bin/fess.in.sh then sets FESS_DICTIONARY_PATH [#3447].
  • A macOS note: Homebrew plus install opensearch-plugins, or Docker.
  • "Configure Fess" says when nothing needs to change [#3447] and lists the cases that still need FESS_DICTIONARY_PATH: OpenSearch installed another way or with --dest elsewhere, more than one OpenSearch under opensearch/, or OpenSearch on another host or port. The excerpt is the 15.9 bin/fess.in.sh, and the notes cover the exported variables.
  • "Verify Installation" mentions bin/fess-setup check.
• install/install-windows.rst: the same tip changes for bin\fess-setup and bin\fess.in.bat [#3447], when "Configure Fess" can be skipped, the 15.9 default of the commented fess.dictionary.path line (C:/opensearch/config/dictionary, as in #3447), and why the path needs /: Fess substitutes it into the index settings, where a backslash is lost.
• install/run.rst: where install opensearch puts OpenSearch, and the root refusal with the chown to recover from it.
• install/troubleshooting.rst: the startup message when no search engine answers, which now names bin/fess-setup install opensearch [#3448].
• install/upgrade.rst: in "Removal of the embedded OpenSearch" only, a paragraph saying that FESS_DICTIONARY_PATH has to match configsync.config_path, when the 15.9 launcher sets it [#3447], and where to set it otherwise.
• install/install.rst: install opensearch is for Linux and Windows, with pointers to the macOS note and the new page.
• admin/plugin-guide.rst: one paragraph on list plugins, list installed, upgrade plugins and remove plugin, with a link to the new page.
• ko only: the install commands for fess-storage-s3 and fess-storage-gcs in admin/fileconfig-guide.rst, and fess-storage-gcs in admin/storage-guide.rst.

quick-start.rst is not changed. It sits outside the version trees and still describes 15.8, whose ZIP bundles OpenSearch, so its ZIP steps belong to the release switch.

Verification

• python3 tools/check_headings.py on the 15.8 and 15.9 trees: passes.
• python3 -m unittest discover -s tools -p 'test_*.py': 79 tests OK. tools/update_eol.py --check and tools/gen_properties_doc.py --check: pass.
• A Sphinx dummy build of each language's 15.9 tree, compared with main: no new warnings in any language, and the new page is built. The same comparison reports an unterminated inline literal and an unknown :doc: target when they are planted in the new page.
• In the doctrees of that build, what this change adds to each page (sections, literal blocks, admonitions, lists and list items, table rows, :doc: references) is the same in all seven languages.
• git merge-tree of this branch with docs(15.9): upgrade guide covers stored Groovy jobs, carried-over config and plugin upgrades #536: no conflicts.
• Commands, options, exit codes and messages were checked against FessSetup.java, Diagnostics.java, fess-setup.properties, bin/fess.in.sh and bin\fess.in.bat on codelibs/fess main and on the branches of #3447 and #3448. On a 15.9.0-SNAPSHOT ZIP, bin/fess-setup was run with no arguments (usage, exit 2), with list (exit 0), list installed (exit 0), install plugins --opensearch-home ... (unknown component: plugins, exit 1), install opensearch-plugins without --opensearch-home (exit 2), remove plugin without a name (exit 2), and install opensearch on macOS (Homebrew and Docker hint, exit 1).

The non-English wording has not been reviewed by native speakers.