feat(docker): derive the agent image's npm CLI list from the catalogue

docker/agent.Dockerfile hardcoded the four npm-published CLIs it installs, one
of the several lists that had to be kept in step with the registry by hand.

It now takes them as `ARG CLI_NPM_PACKAGES`, supplied by
scripts/build-agent-image.mjs from config/clis.stock.json, with the default set
to today's list so a bare `docker build` still produces the same image. The arg
is expanded unquoted because word splitting is what turns the list into several
arguments, which is exactly why every token is validated against
^[@A-Za-z0-9][@A-Za-z0-9/._-]*$ on the producing side; a package name carrying a
space or a metacharacter is refused rather than reaching the RUN line. Verified
by building the layer: four packages in, four arguments out, and the default
still applies with no arg.

The list is filtered on each entry's `enabled` flag — the field whose absence
was the maintainer's §3 finding, where a CLI shipping disabled still got baked
into every image. No stock entry is disabled today, so that assertion would pass
vacuously; a unit test feeds the pure helper a fabricated disabled entry so the
fix is covered now rather than the first time someone ships one.

⚠️ It reads the STOCK catalogue, never the merged registry. A user's
~/.codeman/clis.json must not change what is inside an image tagged
codeman/agent:base, or two machines holding that tag hold different images.

Four CLIs keep hand-written layers because the registry cannot describe what
makes them special: pi's --ignore-scripts, deepseek's pnpm companion and dsh-tui
profile, and the three standalone installers. Rather than extend the schema for
a Docker-only benefit, the coverage test requires each to carry a written reason
AND still be present, so an exclusion cannot quietly become an omission.

There are two producers of this command line and there have to be — the .mjs
cannot import TypeScript, and src/docker-hosts.ts builds the same argv for the
in-app auto-build — so a parity test pins them together, package list, arg pairs
and rendered argv. Their order is pinned too: a different order is a different
RUN string and so a needless cache miss between the two build paths.

docker/server.Dockerfile is deliberately NOT edited (PRs #373 and #377 both
modify it); its narrower list is asserted as a declared omission list instead, so
the divergence is reviewable without touching the file.

Also fixes the in-app hint at index.html, which the new coverage test caught
still omitting omp.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_015EMxQreQUZX5ZyybxAGh12

docker/agent.Dockerfile

@@ -26,13 +26,25 @@ RUN apt-get update \
       openssh-client \
  && rm -rf /var/lib/apt/lists/*
 
-# The npm-published agent CLIs. Pinning is left to the rebuild cadence (see
-# docs/docker-cases-plan.md, user-decision 2).
-RUN npm install -g \
-      @anthropic-ai/claude-code \
-      @openai/codex \
-      @google/gemini-cli \
-      opencode-ai \
+# The npm-published agent CLIs, supplied by scripts/build-agent-image.mjs from
+# config/clis.stock.json so a new stock CLI needs no edit here. The default is
+# today's literal list, so a bare `docker build` still produces the same image.
+#
+# ⚠️ Expanded UNQUOTED on purpose: word splitting is what turns the list into
+# several arguments. Every token is validated against
+# ^[@A-Za-z0-9][@A-Za-z0-9/._-]*$ on the producing side
+# (scripts/lib/cli-catalog.mjs) precisely because of that.
+#
+# ⚠️ Filtered on each entry's `enabled` flag, so a CLI that ships disabled is
+# never baked into every image.
+#
+# Pinning is left to the rebuild cadence (see docs/docker-cases-plan.md,
+# user-decision 2).
+# ⚠️ The default is in REGISTRY order, byte-identical to what the generator emits.
+# A different order is a different RUN string, which is a different layer hash and
+# so a needless cache miss between a bare `docker build` and a scripted one.
+ARG CLI_NPM_PACKAGES="@anthropic-ai/claude-code opencode-ai @openai/codex @google/gemini-cli"
+RUN npm install -g ${CLI_NPM_PACKAGES} \
  && npm cache clean --force
 
 # Antigravity (`agy`) is NOT on npm — Google ships a standalone binary through its