fix: add timeout protection to ProviderSettingsManager initialization

[roomote]

Description

This PR fixes the extension freeze issue reported in #8462 where the extension would hang indefinitely during initialization, particularly affecting Windows users with WSL2.

Problem

The ProviderSettingsManager was calling an async initialize() method in its constructor without proper timeout handling. If the initialization process got stuck (e.g., due to I/O issues or race conditions), the extension would freeze indefinitely with a spinner.

Solution

• Added ensureInitialized() method with configurable timeout (default 10 seconds)
• Implemented initialization tracking to prevent multiple initialization attempts
• Handle initialization errors gracefully to prevent infinite retry loops
• Update constructor to call ensureInitialized() asynchronously with error handling
• All public methods now ensure initialization before proceeding
• Updated tests to handle async initialization properly

Testing

• All existing tests pass ✅
• Added test coverage for timeout behavior
• Verified idempotent initialization
• Tested error scenarios

Impact

This change prevents the extension from freezing during startup while maintaining backward compatibility. The initialization is now non-blocking and will timeout after 10 seconds if it gets stuck, allowing the extension to continue functioning (with potential limitations) rather than hanging indefinitely.

Fixes #8462

---

Important

Adds timeout protection to ProviderSettingsManager initialization to prevent indefinite hangs, ensuring idempotent and error-handled startup.

• Behavior:
  • Adds ensureInitialized() method with a 10-second timeout to ProviderSettingsManager to prevent indefinite hangs during initialization.
  • Updates constructor to call ensureInitialized() asynchronously with error handling.
  • All public methods now call ensureInitialized() to ensure proper initialization.
• Implementation:
  • Introduces initializeWithTimeout() to handle initialization with timeout logic in ProviderSettingsManager.ts.
  • Tracks initialization state with initializationPromise and isInitialized flags.
  • Handles initialization errors by logging and preventing infinite retries.
• Testing:
  • Updates tests in ProviderSettingsManager.spec.ts to handle async initialization.
  • Adds test coverage for timeout behavior and idempotent initialization.
  • Verifies error scenarios and migration processes.

^{This description was created by for a0a75fe. You can customize this summary. It will automatically update as commits are pushed.}

[roomote]

Self-review: performed a deadpan stare into my own constructor and found a race with a timeout having an existential crisis.

[roomote]

[P1] Timeout promise can cause unhandled rejection and isInitialized is set true on error, allowing calls to bypass init. Suggest clearing the timer and not marking initialized on failure.

Suggested change

	const timeoutPromise = new Promise<never>((_, reject) => {
	setTimeout(() => {
	reject(new Error(`ProviderSettingsManager initialization timed out after ${timeoutMs}ms`))
	}, timeoutMs)
	})
	const initPromise = this.initialize()
	try {
	await Promise.race([initPromise, timeoutPromise])
	this.isInitialized = true
	} catch (error) {
	console.error("ProviderSettingsManager initialization failed:", error)
	// Set to initialized even on error to prevent infinite retries
	this.isInitialized = true
	throw error
	}
	}
	let timer: ReturnType<typeof setTimeout> | undefined
	const timeoutPromise = new Promise<never>((_, reject) => {
	timer = setTimeout(() => {
	reject(new Error(`ProviderSettingsManager initialization timed out after ${timeoutMs}ms`))
	}, timeoutMs)
	})
	const initPromise = this.initialize()
	try {
	await Promise.race([initPromise, timeoutPromise])
	this.isInitialized = true
	} catch (error) {
	console.error("ProviderSettingsManager initialization failed:", error)
	throw error
	} finally {
	if (timer) clearTimeout(timer)
	this.initializationPromise = null
	}

[roomote]

[P2] Duplicate error logging and swallowed rejection. initializeWithTimeout already logs the failure; catching here logs again and swallows the rejection. Consider no-op catch to avoid duplicate logs while preventing unhandled rejection warnings.

Suggested change

	console.error("ProviderSettingsManager initialization failed:", error)
	this.ensureInitialized().catch(() => {
	// already logged inside initializeWithTimeout
	})