App kit bug fixes and updates

[hjchen-circle]

This PR:

• addresses the issue raised in Rejected wallet connection leaves App Kit examples unable to retry #6 and supersedes fix(examples): keep wallet connect retryable after rejection #7 and fix(examples): harden empty wallet accounts on connect #8
• also clears the output panel on successful wallet connect
• surfaces the actual Error throw message instead of generic Unknown error
• adds potential troubleshooting guidance for Swap kit in case of bad RPC
• switches out Base Sepolia for Avalanche Fuji for the unified balance kit demo and explains the situation of both EVM and Solana wallet prompts required during the spend operation
• drops the estimate pre-step for send() and swap()
• bumps dependencies to latest versions

Closes #6