Feat: per-window layout memory & Accessibility startup gate

[dranik-by]

No description provided.

[runjuu]

Found several blocking regressions that should be addressed before merging:

1. [P1] Restore the indicator controller and event subscription. AppDelegate no longer creates IndicatorWindowController, and the controller no longer subscribes to activateEventPublisher. As a result, the on-screen indicator, including always-on, auto-show, shortcut, and function-key indicators, can never appear.

2. [P1] Use a stable persisted key for normal-app memory. Normal-app cache keys are written as bundle#pid#window, but process IDs and CG window numbers change when the target application restarts. retrieve supports a bundle fallback, yet save never writes that fallback. Layout memory therefore cannot survive a target-app or Mac restart, and unreachable entries accumulate over time.

3. [P1] Do not silently enable restore-previously-used during migration. Every profile without ISPEnableRestorePreviouslyUsed.v1, including existing users who intentionally disabled the feature, is changed from false to true. This unexpectedly changes input-source switching behavior.

4. [P2] Remove com.apple.security.cs.disable-library-validation unless it is demonstrably required. The entitlement weakens the hardened runtime, while this PR does not add an unsigned-library or plugin-loading requirement.

5. [P2] Keep the shared scheme Run action on Debug. Changing LaunchAction to Release makes normal Cmd+R launches optimized and excludes DEBUG behavior, which impairs development and debugging.

Verification: xcodebuild -scheme "Input Source Pro" -configuration Debug -destination "platform=macOS" CODE_SIGNING_ALLOWED=NO test succeeded with all 66 tests passing. The current tests do not cover indicator construction or persistence across a target-app relaunch.