Moves 5 related docs into docs/devops/gitea-runner/ to keep this
multi-doc workstream from colliding with future roadmaps and
delegation prompts in docs/devops/.
Renames:
HOSTINGER_GITEA_RUNNER_ROADMAP.md -> ROADMAP.md
HOSTINGER_GITEA_ACT_RUNNER_SETUP.md -> ACT_RUNNER_SETUP.md
GITEA_PACKAGES_PUBLISH_WORKFLOW.md -> PUBLISH_WORKFLOW.md
HOSTINGER_GITHUB_RUNNER_SETUP.md -> _PLAN_B_GITHUB_RUNNER.md
CODEX_DELEGATION_PROMPT.md -> (same name, moved)
All internal cross-links updated via sed sweep. Verified no stale
references remain.
Adds README.md in the new folder as the index + pattern doc for
future multi-doc workstreams (one-liner handoff, file map,
architecture summary).
Updated one-liner handoff path:
Read docs/devops/gitea-runner/CODEX_DELEGATION_PROMPT.md ...
