refactor(meta): centralize category/distro SPOTs

categories.yml moves from roles/ to the repository-root meta/, joining packages.yml. utils/roles/categories.py owns its location plus the tree-walking helpers that were stranded in entity/name.py, so no caller spells the path or duplicates the lookup.

meta/distros.yml becomes the SPOT for every distribution: os_family, Galaxy platform name, dev-environment base image, and the pkgmgr/pkgmgr-virgin/environment reference templates. It replaces seven scattered copies (DISTRO_FAMILY, VALID_DISTROS, _DISTROS, _CANONICAL_PLATFORMS, two shell arrays, a Makefile literal). INFINITO_DISTROS is no longer a static default but generated by utils/env/handlers/infinito/distros.py; the shell consumers read it through the env layer.

Drops dead CLI surface found along the way: --categories-file and --roles-dir on the provision CLI plus three unused parameters of generate_dynamic_inventory, and the positional roles_file of the invokable categories command.

tests/lint/repository/test_distros_spot.py pins the copies that cannot call the SPOT (workflow literals, docs table) and forbids composing a pkgmgr reference outside it.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

scripts/github/resolve/pick_distro.sh

@@ -1,16 +1,21 @@
 #!/usr/bin/env bash
 #
 # Decide which distros the latest-push CI run should cover. If the
-# pushed commit carries a `vX.Y.Z` annotated tag, run every distro in
-# `ALL_DISTROS`; otherwise pick one at random. Emits both
-# `is_version` and `distros` to GITHUB_OUTPUT.
+# pushed commit carries a `vX.Y.Z` annotated tag, run every declared
+# distro; otherwise pick one at random. Emits both `is_version` and
+# `distros` to GITHUB_OUTPUT. The distro set comes from INFINITO_DISTROS,
+# which the env layer generates from the meta/distros.yml SPOT.
 #
 # Usage:
 #   pick_distro.sh
 #   (reads GITHUB_SHA from env; writes to GITHUB_OUTPUT)
 set -euo pipefail
 
-ALL_DISTROS=(arch debian ubuntu fedora centos)
+REPO_ROOT="$(cd "$(dirname "${BASH_SOURCE[0]}")/../../.." && pwd)"
+# shellcheck source=scripts/meta/env/load.sh
+source "${REPO_ROOT}/scripts/meta/env/load.sh"
+: "${INFINITO_DISTROS:?INFINITO_DISTROS must be resolved by scripts/meta/env/load.sh}"
+read -r -a ALL_DISTROS <<<"${INFINITO_DISTROS}"
 
 version_tag="$(
 	git tag --points-at "${GITHUB_SHA}" |