Fix script terminal commands returning errors after dispatch

[Stella Huang (StellaHuang95)]

Context

The existing normal and dedicated script-terminal command handlers dispatch the script successfully, then fall through to the invalid-context error because the successful branches do not return.

This affects any caller using these existing commands; it is not specific to PEP 723.

Why this change is needed

A script can start running while the command promise rejects, causing callers to report failure after successful dispatch. The false error also makes command completion inconsistent with the underlying terminal operation.

What changed

• Return after successful normal terminal dispatch.
• Return after successful dedicated terminal dispatch.
• Preserve invalid-context errors for non-URI inputs and URI inputs without a project or environment.

Behavior and compatibility

• No command, menu, setting, view, or status-bar contribution is added.
• Environment resolution and fallback are unchanged.
• Terminal selection/reuse, cwd, arguments, visibility, and activation behavior are unchanged.
• The only success-path difference is that the command now resolves instead of throwing after dispatch.

Reviewer guide

1. Review the two production return statements.
2. Review success coverage for resolved and fallback environments.
3. Review invalid and missing-context regressions.

Validation

• npm run compile-tests --silent
• Targeted command and terminal manager suites: 33 passing
• ESLint on changed TypeScript files
• git diff --check

[Heejae Chang (heejaechang)]

🔒 Automated review in progress — Heejae Chang (@heejaechang) is auto-reviewing this PR.

[Heejae Chang (heejaechang)]

Verification: The relevant tests could not be fully run in the isolated environment; this review is not fully verified.

[Heejae Chang (heejaechang)]

Approved via Review Center.