Switch the default of --strict to true

[DanielRosenwasser]

Fixes #62333

[Copilot]

Pull request overview

This PR changes the default value of the --strict compiler option from false to true. This is a significant breaking change that enables all strict type-checking options by default.

Changes:

• Modified the strict option default handling to return true when the option is undefined (instead of false)
• Updated the command-line parser metadata to reflect the new default value of true
• Regenerated test baselines to reflect the new stricter type checking behavior

Reviewed changes

Copilot reviewed 284 out of 13088 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/compiler/utilities.ts	Modified getStrictOptionValue to default to true when strict is undefined
src/compiler/commandLineParser.ts	Updated defaultValueDescription for strict option from false to true
tests/baselines/reference/*.js	Added "use strict"; directive to generated JavaScript files
tests/baselines/reference/*.errors.txt	Added new type-checking errors caught by stricter defaults (uninitialized properties, implicit any types, etc.)
tests/baselines/reference/*.types	Updated type inference results to reflect stricter type checking

[jakebailey]

Pretty shocked there are no changes to any unit tests or related baselines; I verified locally too