Trigger restartRpc when envVars changed

[jthuangarm]

Fixes

• #131

Changes

Introduce a new event to notify when environment variables change, and integrates this event into the solution management workflow, e.g. restartRpc. By doing this, restartRpc will be triggered immediately after entering environment variables in Settings and pressing the OK button.

• Added a new onDidChangeEnvVars event to the EnvironmentManager interface.
• Registered the event emitter for disposal in the extension's subscriptions to ensure proper cleanup.
• Avoid frequent/duplicate RPC restarts even when the resulting env vars are identical (e.g., extensions changing like (un-)installing extensions that are unrelated to Keil Studio).
• Updated SolutionManagerImpl to accept an EnvironmentManager instance and listen for the new onDidChangeEnvVars event, triggering debouncedHandleEnvironmentChange when environment variables are updated.

Testing and Verification:

• Added tests to verify that the onDidChangeEnvVars event fires on environment initialization and configuration changes.
• Added a test to ensure that when environment variables change after a solution is activated, the system requests an RPC restart as expected.

Checklist

• 🤖 This change is covered by unit tests (if applicable).
• 🤹 Manual testing has been performed (if necessary).
• 🛡️ Security impacts have been considered (if relevant).
• 📖 Documentation updates are complete (if required).
• 🧠 Third-party dependencies and TPIP updated (if required).

[Copilot]

Pull request overview

Adds an EnvironmentManager event to detect environment variable updates and wires it into SolutionManagerImpl so environment changes can trigger an RPC restart flow (via debounced environment-change handling), with unit tests covering the new behavior.

Changes:

• Introduces EnvironmentManager.onDidChangeEnvVars and fires it when the environment variable collection is updated.
• Injects EnvironmentManager into SolutionManagerImpl and listens for env-var changes to trigger the existing debounced environment-change handling (restart RPC path).
• Adds unit tests verifying the env-var change event and that a post-activation env-var change requests an RPC restart.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
src/solutions/solution-manager.ts	Injects EnvironmentManager and subscribes to env-var change events to trigger debounced environment change handling.
src/solutions/solution-manager.test.ts	Adds coverage to ensure env-var changes after activation request restartRpc.
src/desktop/extension.ts	Passes the existing envManager instance into SolutionManagerImpl.
src/desktop/env-manager.ts	Adds onDidChangeEnvVars event and fires it after updating the environment variable collection.
src/desktop/env-manager.test.ts	Adds tests asserting onDidChangeEnvVars fires on init and config updates.