您如何正确处理异常？

<?php
try {
    $data = riskyOperation();
} catch (InvalidArgumentException $e) {     // catch a SPECIFIC type first
    handleBadInput($e->getMessage());
} catch (DatabaseException $e) {
    handleDbError($e);
} catch (Throwable $e) {                     // catch-all (Error OR Exception) — last
    logError($e);
    throw $e;                                 // re-throw what you can't handle
} finally {
    cleanup();                                // ALWAYS runs (success or failure)
}

// throwing
if ($amount < 0) {
    throw new InvalidArgumentException("Amount must be positive, got $amount");
}

// a custom exception for your domain
class InsufficientFundsException extends Exception {
    public function __construct(private float $shortfall) {
        parent::__construct("Short by $shortfall");
    }
    public function getShortfall(): float { return $this->shortfall; }
}
throw new InsufficientFundsException(50.0);

try {
    $db->query(...);
} catch (PDOException $e) {
    // wrap with context, preserving the original as the "previous" exception
    throw new RepositoryException("Failed to load user", 0, $e);
}

✓ Catch SPECIFIC exceptions, not a blanket Throwable (unless intentionally last)
✓ Don't swallow exceptions silently (empty catch) — log or re-throw
✓ Use finally / proper cleanup for resources (files, connections)
✓ Create meaningful custom exceptions for domain errors
✓ SECURITY: log details internally; show users a generic message (don't leak
  stack traces / internal info — display_errors off in production)