Use UID instead of handle to identify extensions in app-watcher

[isaacroldan]

WHY are these changes introduced?

switch from using extension handles to UIDs as the primary identifier for extensions in the app watcher.

WHAT is this pull request doing?

• Updates extension diffing to compare UIDs instead of handles
• Modifies UUID generation to be deterministic based on the extension handle
• Use UID in the whole app-watcher/dev-session flow.
• Adds some code to detect folder movements.

How to test your changes?

1. Create a new app with multiple extensions
2. Start the dev server
3. Try moving extension folders around (inside the extensions folder)
4. Verify that extensions are properly tracked and rebuilt
5. Test deleting extensions and confirm proper cleanup

Checklist

• I've considered possible cross-platform impacts (Mac, Linux, Windows)
• I've considered possible documentation changes

[isaacroldan]

• Use UID instead of handle to identify extensions in app-watcher #5150 👈 (View in Graphite)
• main

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[github-actions]

We detected some changes at packages/*/src and there are no updates in the .changeset.
If the changes are user-facing, run "pnpm changeset add" to track your changes and include them in the next release CHANGELOG.

[github-actions]

Coverage report

St.❔	Category	Percentage	Covered / Total
🟡	Statements	75.24% (+0.02% 🔼)	8854/11768
🟡	Branches	70.51% (+0.04% 🔼)	4296/6093
🟡	Functions	75.15% (+0.01% 🔼)	2317/3083
🟡	Lines	75.79% (+0.03% 🔼)	8371/11045

Show files with reduced coverage 🔻

St.❔	File	Statements	Branches	Functions	Lines
🟢	... / app-event-watcher.ts	93.83% (-1.23% 🔻)	86.49%	90.48%	98.61%

Test suite run success

1996 tests passing in 903 suites.

Report generated by 🧪jest coverage report action from 66b63f7