Fix needs_approval field in BrowserHand::new() from false to true to
match the TOML config (hands/browser.HAND.toml says requires_approval = true).
Browser automation has security implications and should require approval.
Add 11 unit tests covering:
- Config id and enabled state
- needs_approval correctness (after fix)
- Action deserialization (Navigate, Click, Type, Scrape, Screenshot)
- Roundtrip serialization for all major action variants
- BrowserSequence builder with stop_on_error()
- Multi-step sequence execution
- FormField deserialization
Also add stop_on_error() builder method to BrowserSequence which was
referenced in the test plan but missing from the struct.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
17a2501808