Revert "sessions - remove CLI support (not used)"

[bpasero]

Reverts #295801

[vs-code-engineering]

📬 CODENOTIFY

The following users are being notified based on files changed in this PR:

@deepak1556

Matched files:

• src/vs/code/electron-main/app.ts

[Copilot]

Pull request overview

Reverts prior removal of Sessions CLI support by reintroducing a --sessions flag that launches the Sessions window from the CLI and wiring it through argument parsing into the Electron main startup path.

Changes:

• Add --sessions to native CLI option descriptions and NativeParsedArgs.
• Update macOS CLI launching logic to prefer launching an embedded app when --sessions is used.
• Make Electron main open the Sessions window on startup when --sessions is present (or when running as an embedded app).

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
src/vs/platform/environment/node/argv.ts	Re-adds --sessions to CLI option help/definitions.
src/vs/platform/environment/common/argv.ts	Extends NativeParsedArgs with sessions?: boolean.
src/vs/code/node/cli.ts	Adds macOS --sessions handling to launch an embedded app and adjusts argv passing.
src/vs/code/electron-main/app.ts	Opens Sessions window at startup when --sessions is provided.

Comments suppressed due to low confidence (1)

src/vs/code/node/cli.ts:510

• readdirSync(applicationsPath) can throw (e.g. permission/IO errors) even when existsSync(applicationsPath) is true, which would crash the CLI when --sessions is used. Wrap the directory scan in a try/catch and handle failures gracefully (e.g. fall back to launching the main app, or emit an error that includes the underlying exception).

				const contentsPath = dirname(dirname(process.execPath));
				const applicationsPath = join(contentsPath, 'Applications');
				const embeddedApp = existsSync(applicationsPath) && readdirSync(applicationsPath).find(f => f.endsWith('.app'));
				if (embeddedApp) {