feat(claude): persist New Session defaults

[yaroshevych]

Summary

I noticed that when starting Claude from agent-deck, the New Session dialog behaved inconsistently. Turns out, it didn't save Claude parameters between restarts. In this PR:

• persist Claude New Session defaults for permission mode, Chrome, teammate mode, and extra args in config.toml
• restore those defaults when reopening New Session after agent-deck restarts
• document the new Claude config keys in the agent-deck skill references

Tests

Manually tested:

• Open agent-deck, create new Claude session, with custom parameters
• Close agent-deck
• Open agent-deck, create new Claude session → custom parameters persist

Unit tests:

• go test ./internal/ui
• go test ./internal/session -run 'TestClaudeExtraArgsConfigRoundTrip|TestNewClaudeOptions_WithConfig|TestExtraArgsRestartPersist|TestResumeCommandAppendsExtraArgs'

Note: full go test ./internal/session still has existing tmux bootstrap failures in this environment.