Instead of blocking the entire UI with "Activating best chain..." until
the daemon finishes warmup, treat warmup responses as a successful
connection. The wallet now:
- Sets connected=true + warming_up=true when daemon returns RPC -28
- Shows warmup status with block progress in the loading overlay
- Polls getinfo every few seconds to detect warmup completion
- Allows Console, Peers, Settings tabs during warmup
- Shows orange status indicator with warmup message in status bar
- Skips balance/tx/address refresh until warmup completes
- Triggers full data refresh once daemon is ready
Also: fix curl handle/header leak on reconnect, fill in empty
externalDetected error branch, bump version to v1.2.0 in build scripts.
915c1b4d23