test: Introduce lockfile to all Scenario tests

[Tonisal-byte]

This pull request refactors how lock files are created and managed in scenario and unit tests, improving test readability and consistency. It introduces helper functions to simplify lock file creation, updates documentation to reflect these changes, and replaces manual lock file writing with the new helpers throughout the test suite.

Test infrastructure improvements:

• Added writeLockInDir helper in scenario/component_changed_test.go to simplify writing lock files in scenario tests, replacing manual file creation with a single function call.
• Introduced localComponentLock helper in scenario/component_render_test.go for consistent lock file creation in component render tests.
• Updated dynamicTestProject in projecttest/dynamictestproject.go to maintain a map of lock files, enabling programmatic lock file management and serialization. [1] [2]

[Copilot]

Pull request overview

Note

Copilot was unable to run its full agentic suite in this review.

Adds first-class lockfile support to scenario dynamic test projects, allowing tests to generate and update component lockfiles via helpers instead of handwritten TOML strings.

Changes:

• Introduces projecttest.AddLock(...) (serialize-time) and projecttest.WriteLock(...) (post-serialize updates) utilities for scenario fixtures.
• Extends dynamicTestProject to track and serialize component lockfiles (including when initializing a git repo).
• Updates scenario tests and testing guidance to use the new lock helpers.

Reviewed changes

Copilot reviewed 8 out of 9 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
scenario/testdata/simple/locks/a.lock	Adds a basic lockfile fixture used by simple scenario testdata.
scenario/internal/projecttest/lockfile_test.go	Adds unit tests validating lock serialization, updating, and conflict handling.
scenario/internal/projecttest/lockfile.go	Adds lockfile option helpers and filesystem writing helpers for scenario projects.
scenario/internal/projecttest/dynamictestproject.go	Adds lock tracking/serialization to dynamic test projects and prevents AddFile/AddLock path conflicts.
scenario/component_render_test.go	Switches render scenario fixtures from raw lockfile strings to AddLock.
scenario/component_query_test.go	Adds a lockfile to the query scenario fixture via AddLock.
scenario/component_changed_test.go	Replaces ad-hoc lockfile string writes with projecttest.WriteLock helper.
scenario/component_build_test.go	Adds a lockfile to the build scenario fixture via AddLock.
.github/instructions/testing.instructions.md	Documents how to create lock files in unit tests vs scenario fixtures.