feature: bash completes the vpn-* commands, their options and the names they take.

ADR.md

@@ -1043,3 +1043,25 @@ HTTPS, a public name and the web service. Clients are managed like service accou
 it renames it in the clients. The signing key does not rotate; replacing it invalidates every ID
 token issued. Wrong client secrets lock the client like any account. The implicit and hybrid
 flows, dynamic client registration and public clients without a secret are not offered.
+
+## ADR-38: Bash completions are files per command in bash-completion's completions directory
+
+Status: Accepted
+
+Context: The `vpn-*` commands have many subcommands, options and names (users, groups, issuing
+CAs, templates, settings) that are hard to remember. bash-completion's README recommends its
+`completionsdir`, `/usr/share/bash-completion/completions` on Ubuntu, whose files it loads on the
+first Tab of their command, and calls the eagerly loaded `/etc/bash_completion.d` not
+recommended; it prefers the name `<command>.bash`, which noble's 2.11 and resolute's 2.16 both
+look up.
+
+Decision: The package installs `<command>.bash` for each `vpn-*` command into
+`/usr/share/bash-completion/completions` and recommends `bash-completion`. The completions read
+the names they offer from the commands themselves (`--json list`) or the package's Python
+modules (the schema, the configuration, the PKI's templates and reasons), not from copies, and
+send errors to `/dev/null`, so a user who may not read them gets the fixed words only.
+
+Consequences: Completions follow the code without being edited for each new setting or name. A
+Tab that offers names runs a command or Python, which takes a fraction of a second. The files
+are not conffiles; an administrator overrides one in `/etc/bash_completion.d` or the user's own
+completions directory.