feat(client): retry PermissionDenied on established connections (opt-in)

[sachinsharma3191]

Summary

• Adds retry_permission_denied_when_established flag to RetryOptions (default: false), so existing behavior is unchanged.
• Tracks "established" state per-connection via an Arc<AtomicBool> on ConnectionInner, set to true after the first successful RPC response.
• In TonicErrorHandler::handle(), PermissionDenied is retried only when both the opt-in flag is enabled and the connection is established — this handles transient auth failures (token rotation races, IAM propagation delays) without retrying genuinely unauthorized initial connections.
• Scoped to PermissionDenied only; Unauthenticated is left to credential refresh flows.

Open design questions (for reviewer)

1. Config location: Flag is on RetryOptions (flows through ConnectionOptions.retry_options). Alternative: a dedicated field on ConnectionOptions. Current placement keeps retry concerns together.
2. "Established" lifetime: The flag is sticky per ConnectionInner (never resets on reconnect). This is intentional — if creds were valid once, a PermissionDenied on a reconnected transport is likely transient. If reset-on-reconnect is desired, we'd need a callback from the transport layer.

Addresses #1448

Test plan

• permission_denied_not_retried_by_default — default behavior unchanged
• permission_denied_not_retried_when_not_established — opt-in enabled but no successful RPC yet → not retried
• permission_denied_retried_when_established_and_opted_in — opt-in + established → retried
• All 158 temporalio-client lib tests pass
• All 389 temporalio-sdk-core lib tests pass
• Full workspace cargo build succeeds