Support workspace projects in Packse scenarios

[zanieb]

Summary

• Add inline [root.workspace.project] metadata to Packse scenarios.
• Render pyproject.toml structurally from the scenario root requirements, Python constraint, project identity, and required environments.
• Use the same materializer in generated lock tests and bespoke workflow tests.
• Reject unknown workspace fields, non-universal workspace scenarios, and attempts to overwrite an existing project.
• Centralize Packse index configuration for project commands.

Why

The scenario should fully define the root project used by a lock case. This extends the existing root scenario abstraction without a separate workspace-scenario tree or an external handwritten workspace fixture.

Stack

1. This pull request
2. Add Packse marker reachability scenario #20014
3. Test marker reachability workspace workflow #20015

Validation

• cargo test --package uv-test packse::scenario::tests
• cargo test --package uv-dev generate_scenarios::tests
• cargo clippy --package uv-test --package uv-dev --all-targets -- -D warnings
• cargo fmt --all -- --check

[astral-sh-bot]

uv test inventory changes

This PR changes the tests when compared with the latest main baseline.

• Added tests: 19
• Removed tests: 1
• Changed suites: 7

uv-dev: +1 / -0

Added:

• uv-dev::generate_scenarios::tests::workspace_lock_scenario_uses_shared_materializer

Removed: none

uv-resolver: +1 / -0

Added:

• uv-resolver::lock::tests::dependency_marker_preserves_parent_conflicts

Removed: none

uv-test: +6 / -0

Added:

• uv-test::packse::scenario::tests::materialize_root_workspace
• uv-test::packse::scenario::tests::materialize_root_workspace_does_not_overwrite
• uv-test::packse::scenario::tests::materialize_root_workspace_requires_configuration
• uv-test::packse::scenario::tests::parse_root_workspace
• uv-test::packse::scenario::tests::reject_root_workspace_for_non_universal_scenario
• uv-test::packse::scenario::tests::reject_unknown_root_workspace_field

Removed: none

uv::lock_scenarios: +1 / -0

Added:

• uv::lock_scenarios::lock_conflict::extra_conflict_discovery_respects_parent_reachability

Removed: none

uv::project: +0 / -1

Added: none

Removed:

• uv::project::workflow::jax_instability

uv::tool: +8 / -0

Added:

• uv::tool::tool_install::tool_install_lock_refreshes_local_directory_constraint
• uv::tool::tool_install::tool_install_lock_revalidates_changed_constraints
• uv::tool::tool_install::tool_install_lock_supports_local_wheel
• uv::tool::tool_install::tool_install_lock_verifies_hashes
• uv::tool::tool_install::tool_install_locks_are_preview
• uv::tool::tool_upgrade::tool_upgrade_lock_uses_requested_python
• uv::tool::tool_upgrade::tool_upgrade_lock_verifies_hashes
• uv::tool::tool_upgrade::tool_upgrade_writes_preview_lock

Removed: none

uv::workspace: +2 / -0

Added:

• uv::workspace::workspace_list::workspace_list_scripts
• uv::workspace::workspace_metadata::workspace_metadata_dependency_edges_include_parent_reachability

Removed: none