basectl activate fails when project venv lacks Click #2610

Goal

Make basectl activate <project> work for projects whose virtual environment does not contain Base's Python dependencies.

Background

Base correctly installs Click into the Base-owned virtual environment during basectl setup, while a uv-managed project such as bleach owns a separate .venv containing only its declared dependencies. During runtime-shell startup, Base invokes base_projects activation-sources through base-wrapper without selecting the Base project. base-wrapper therefore runs that Base control-plane package with the project Python, and base_cli fails to import Click. The user then receives the misleading secondary error Unable to resolve project activation scripts.

Related to the broader control-plane/runtime separation tracked by #1611.

Scope

• Route runtime activation-source discovery through the Base-owned Python runtime.
• Preserve the project virtual environment activation and project-owned activate.source behavior.
• Add a regression fixture that has a project Python executable but no Click installation.
• Keep the change narrow; do not make Click or base-cli a project dependency.

Acceptance Criteria

• basectl activate <project> succeeds when the project .venv lacks Click and the manifest has no activate.source entries.
• Manifest-declared activation scripts are still resolved and sourced from the project root.
• The Base runtime invokes base_projects activation-sources with the Base control-plane environment.
• Existing runtime-shell, project-command, and full Base validation tests remain green.
• The error path does not report the generic activation-resolution failure for a missing Base control-plane dependency without preserving the underlying diagnostic.

Validation

• Focused cli/bash/commands/basectl/tests/runtime-shell.bats regression coverage.
• Relevant Base Python project-discovery tests.
• basectl test base and git diff --check.
• Reproduce with a uv-style project environment containing no Click.

Non-Goals

• Do not add Click, base-cli, or other Base dependencies to downstream project manifests.
• Do not redesign base-wrapper project-command routing.
• Do not change project-owned command, test, build, or demo execution environments.

Project Fields

• Status: In Progress
• Priority: P1
• Size: S
• Area: Runtime
• Initiative: Adoption Polish

Agent Assignment

• Assigned to: codeforester
• Implementation: issue-backed worktree and pull request linked to this issue.