Feature: Add location + timezone settings entities

[MTrab]

Summary

Add HA entities/services for location and timezone settings.

Why this matters (Most-Value)

Improves contextual robot behavior and can be automation-driven.

SDK evidence (no wire-pod dependency)

• RPC: UpdateSettings, PullJdocs
• Proto field support in RobotSettingsConfig:
  • default_location
  • time_zone

Proposed HA design

• text.default_location
• select.time_zone (or text.time_zone)
• DISABLED by default

Acceptance criteria

• Values read from ROBOT_SETTINGS jdoc.
• Writes validate non-empty inputs and update HA state.
• Tests and translations included.