[eas-simulator] agent-device screenshot --scale, --max-size removed

[gwdp]

Why

agent-device PR #1617 adds a scale-only screenshot --scale knob and removes --max-size. Our controller reference told agents the opposite: that agent-device screenshots are "full-resolution with no scale knob."

How

• Rewrote the agent-device screenshot note in references/controllers.md:
  • screenshot --scale <0.01–1> resizes both dimensions, 1 = full resolution.
  • Token-conscious default via AGENT_DEVICE_SCREENSHOT_SCALE / screenshotScale in config, overridden by an explicit --scale.
  • --max-size is removed and older calls are refused with migration guidance.
  • Added a remote-session caveat: the resize runs on the daemon, so a newer client against an older EAS session daemon can have --scale silently ignored.
• Gated the whole thing on v0.20.6 as a single token, easy to bump if it ships as a different version.
• Bumped the plugin version to 1.9.7.

Test Plan

• Cross-check every claim against agent-device#1617's own doc changes: flag name, the 0.01–1 range, the env var / config key, and the --max-size removal

[szdziedzic]

awesome