fix(ci): install template nodes into root venv before pytest (#1843)

The cli-python job's "Test Python template project" step has been
failing on every main commit since #1820 ("feat(uv): per-node
managed Python venvs at build + runtime", commit 6ae0fa9) --
5+ merged commits all red, blocking the Trunk merge queue alongside
the ros2-bridge regression that #1839 just resolved.

Root cause
==========

#1820 changed `dora build --uv` to install each node package into
its own managed venv at `.dora/python-envs/<node>/` (good for
deterministic per-node deps + no cross-node contamination). But the
`dora new --lang python` templates generated test stubs at
`tests/test_<node>.py` do:

    from <node>.main import main

The CI step pytest invocation is `uv run pytest` from the
test_python_project root, which resolves against the ambient venv
(VIRTUAL_ENV set by the earlier setup-python-uv step to the
repo-level .venv/). That venv has dora-rs + pyarrow + pytest + ruff
but no node packages -- those are in the per-node venvs. Pre-#1820,
`dora build` installed nodes into whatever venv was active, so the
imports worked.

Actual failure from CircleCI v1.1 API log on main HEAD (job 5882,
step "Test Python template project"):

    FAILED listener-1/tests/test_listener_1.py::test_import_main
      > from listener_1.main import main
      E ModuleNotFoundError: No module named 'listener_1'
    FAILED talker-1/tests/test_talker_1.py::test_import_main
      > from talker_1.main import main
      E ModuleNotFoundError: No module named 'talker_1'
    FAILED talker-2/tests/test_talker_2.py::test_import_main
      > from talker_2.main import main
      E ModuleNotFoundError: No module named 'talker_2'
    3 failed, 3 passed

Fix
===

After `dora build --uv` (which sets up the per-node venvs), also
install the three node packages into the active venv so `uv run
pytest` at the project root can resolve their imports:

    uv pip install -e listener-1 -e talker-1 -e talker-2

This preserves the per-node-venv isolation that #1820 introduced
(those venvs still drive `dora build` and `dora run`) while giving
the test pass a venv that sees all node packages. The root venv is
ephemeral and only used by this CI step, so no production
contamination.

Scope notes
===========

* CI-only fix; the `dora new` template itself is unchanged. Users
  running `pytest` in their own `dora new` projects will hit the
  same issue, but fixing that requires a template-level change
  (e.g. root pyproject.toml that path-depends on each node, or a
  documented "for testing, also pip install -e <node>/" step in
  the README). That is a separate follow-up; this PR keeps scope
  to "unblock the merge queue."
* The hardcoded node names listener-1, talker-1, talker-2 match
  the `dora new --lang python` template (see
  binaries/cli/src/template/python/mod.rs:126-130). If that
  template grows or shrinks the node set, this list needs to
  follow. A loop over `*/pyproject.toml` would be more robust but
  also more clever-shell; keeping the explicit list for clarity.

Validation
==========

Local repro is awkward (the CI step builds the whole dora CLI from
source first), but the failure mode is mechanically obvious from
the log and the fix is a one-line `uv pip install -e` of the same
packages the build step references. CircleCI will validate on this
PR.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: heyong4725

.circleci/config.yml

@@ -623,6 +623,17 @@ jobs:
             cd test_python_project
             dora build dataflow.yml --uv
             uv run ruff check .
+            # #1820 introduced per-node managed Python venvs at
+            # `.dora/python-envs/<node>/`, so `dora build --uv` no
+            # longer leaves the node packages installed in the
+            # ambient venv. The template's generated test stubs do
+            # `from <node>.main import main` and the project root has
+            # no top-level pyproject for `uv run pytest` to resolve
+            # against, so the imports fail with ModuleNotFoundError.
+            # Install each node into the active venv for the test
+            # pass; the per-node venvs continue to drive `dora build`
+            # / `dora run` themselves.
+            uv pip install -e listener-1 -e talker-1 -e talker-2
             uv run pytest
             export OPERATING_MODE=SAVE
             dora build dataflow.yml --uv